Ok guys now that I've put some miles on my new Duster I've realized that I need to take more gear out of the car for those longer distance car shows.

I have a stroked big block with alot of torque, 727, 3.55 gears, and 28" tires(275/60/15), converter is a 9.5" Dynamic. It is great around town but when I hop on the highway it gets a little annoying to me since I had a car with a 6 speed manual before.

On a 55 mph road I'm around 2500 RPM's, on the highway at 60 I'm at 2800 RPM's.
I cannot afford an overdrive or a manual trans right now, there's a place near me that can cut a converter apart and re-stall it for less than $200, sometimes with 3 people in the car I can feel the converter slip a little, but my highway RPM's indicate that it locks up fairly well at speed.

So I'm thinking that for around $400 I could switch to 3.23 gears and have the converter tightened up a little. Maybe this would put me at around 2300-2400 at 60 MPH?
What do you guys think? This car is a blast, just trying to make it a little more drivable as we are starting to venture out to more and more car shows/cruises.
Thanks.

I have always been a fan of 3.23 gears, I had them in a 69 GTX with a 572 stroker it ran 11.0 @124.95 thru the quarter mile, I also drove it to Vegas to Mopars at the strip many times from Phoenix. If the car has decent HP 3.23 gears work great all around

Ran 4.10's with 28" tires forever in my 64 300.

Running 3.55's with 26" tires in my 65 Cuda.

No OD in either.

Nice Duster! It sounds like you spend more time on the hiways than I do.

I have ran 3.91s behind my big blocks forever. But I am comfortable running 55ish on my trips which are usually an hour or two at most. The bulk of my driving time is stop and go kinda stuff around the local towns where lower gears are more fun.

Thanks! To be honest the longest I've been on the highway is 30 minutes and that was enough for me lol. We are planning some cruises that are an hour each way so I'd really like to bring the RPM's down and as mentioned, the 500" motor doesn't care what gear is back there, it's an animal with 3.55's so I'm sure 3.23's would be fine, heck a 3.08 would be great but I've only seen 3.23 and old 2.76's available.

I had a friend that put 3.23's in his car and his converter would slip to 3800 just trying to drive around town since it was way too loose for highway gears and wasn't locking the converter up, that's why I'm thinking of tightening mine up some since I've already experienced some slip with 3 people in the car.

My last couple Mopars ran 9's in the 1/4 mile with 4.56 gears and 8" converters so this highway cruising stuff is new to me lol. I'm dying to get a GearVendors overdrive $$$.

I have been around the block on this and have THIS to report:

High stall converters and taller (Lower numerically) gearing do result in excessive slippage, sorta negating the advantage of the taller gearing. I ran a Gear Vendors overdrive with a 3.91 gear, 28" tire and a slippy 9.75 converter. Not fun. The car felt lazy at freeway speeds, like a boat in the water in terms of part throttle feel. The combo was fine for wide open throttle, it just sucked for everything else. I don't care to drag race, I enjoy distance drives, cruises, cornering on twisty roads and such.
I eventually sold the GV and went with a 3.55 gear and an 11" converter that made a huge difference in how the car feels. I really like this combination.

FrankenDuster I love that Charger! What RPM are you at when going 55 and 60?
We were at the GoodGuys Columbus show a couple weeks ago and I am hooked on Pro-Touring. A nice looking good handling car that you can drive anywhere is awesome. I've always been a drag car guy, so with this Duster I had to figure out the cooling, now I'm trying to sort out the converter slippage, next will be getting rid of these skinny bias-ply front tires that suck on the road with big radials out back.

I think what I need to do is to change converters, or have this one adjusted(might call Dynamic), THEN if the converter doesn't make a huge change I'll go to 3.23 gears/

i run 3.23's in both my cars, one with 28" tire. holding out for a "deal" on some 2.94's.

A stroked big block don't need 355s on the street, I think 323s would be perfect also.

I made the mistake of putting 354s behind my 440/6 10 years ago and it don't need 354s, 323 or there a bouts would have been better. It ain't no SB.

Funny when I was young it was 411s for years, no ands, ifs or buts about it. Cars rarely ever saw the highways.

Then I went to 355s and 354s about 15-20 years ago.

Now I'm thinking 323s would be more my style, sucks getting old!

I even have set of 276s I am going to put in for messing around out at Bonneville along with some MT 30" tall tires, should be interesting.

I would also send your convertor to whoever built it if possible and have it made just for your combo...323 gear and all including the camshaft and all. If not the the guy who made it, many places can to do that for you.

I have had Coan Trans build me convertors and trans("street fighter" 727 trans used to cost 600 bucks plus a good core=deal. Convertor was extra but very reasonable, not like a racing convertor, way cheaper) for my 340 and my 440/6 for the street. They did a great job, never ever ever had such great performing trans, seem to match my combo perfectly and could not be happier. And now both of them are over 10 years old and still barking the tires on the upshift.

2800 rpm @ 60 mph = 9.5% slip. That is not good in my opinion but I don't have experience with highway slip only at the track.

I have had converters slip as much as 13% at the finish line. My current Frank Lupo 9 inch in the race car slips 4% through the traps.

My new build will have a Lupo 9.5 inch converter (its currently in the street car). I will be running 4.56 gear with a 30 inch tire but do have a Gear Vendors OD for it. That drops the 4.56 to a 3.55 gear. It will be interesting to see how it behaves on the highway.

Heck, you have the torque. Throw on some 2.76's on there and have some fun.

275/60/15 rear tires that original poster has are pretty large diameter that cuts the effective gear ratio down.

Your overall ratio is about 50 rpm more than a bone stock 71 340 Duster with 3.23 gears and F-70-14 tires. They sold 1,000 of Dusters and Demons like that.

These are not new cars. They drove originally down the road at 3100 at 70 mph.

A F70/14 that originally came with 340 dusters is 26" diameter.

275/60/15 are 28" diameter.

This is a very handy quick visual tool to figure out rear end ratio changes: http://vexer.com/automotive-tools/speed-rpm-calculator

What is the exhaust system on the car? Full to the back, turn downs, Flowmasters even?

My 67 Coronet R/T with the stock 440/727 in it has 294 butt gears.. I feel it still revs too high on the freeway.. The car has 245/15" tires on it. ( I have no idea on tire height...

Have always wanted to install 355 with a GV overdrive...

In high school my everyday driver A12 car had 410 gears in it.. Utterly ridiculous gears to run on the street.. 42 years later I still remember what a PITA that car was with those gears... NEVER AGAIN in a car driven on the street....

245/60-15 are 26.6 inch height..........

That speed calculator is really cool, I'll have to play around with that. But everything else you said I'm already aware of, it's just my personal preference to bring the RPM's down. I've seen guys pound their chest and brag about how they roll down the highway for 2 hours at 3900 RPM's, who the heck wants to do that lol.
I can pretty much drive the car anywhere right now, just want to make the drive more pleasurable, I'm installing my stereo today.

I run 3" pipes with turbo mufflers and turndowns right before the axles. I plan to install some tailpipes this winter to the back bumper.

My 69 Dart had less then 3% slip at the finish line, it was a great ATI converter. I like 5% or less, some 8" converters are useless on the street.
You'll love the Gearvendors, hopefully you're converter is tight enough for it. There's a fine line cuz I had a 10" nitrous converter years ago that was a super tight pig without nitrous of course.

Guys that don't want to pay $2000+++ for high horsepower and high torque handling overdrive conversions.



3" pipe is louder than 2 1/2" but I realize you have a 500 cubic inch air pump to handle.

Pipes out the back will help.

My 67 Coronet has a 493 with a 9.5 dynamic convertor with a gear vendors and 3.55. All I can say is I love the combo. Haven't had it to the track though so don't ask me for a number.

The 68 charger has a mild 406 small block with a TCI Sat night special, probably 2200rpm stall, 904, and 2.94 gears. It slips a bit more than my dynamic while cruising but still isn't that bad on the highway.
I ran it once at the track and got a 13.28 at 101 just using 1st. and 2nd.
I would say not bad for a car with a/c, power steering and lots of sound deadener.

Bob, would going to a 29" tall rear tire help??

Following this.
My 526 made 630lbft at 3600.
i drive it a bunch, and a lot of hiway driving.
i have 3.73's now, and 60 is about 2900 with 275/60's. i'd like to go to 3.23's, so i can at least keep up with traffic.
i had no problem spinning my old motor 4,000+ on the hiway, but not with this engine.
I also have a 2600 Ultimate converter.

You guys have really nice street combos! I have a healthy motor and I think this car would run easy 10's in street trim but I really don't plan on racing it at all and just want to make it more streetable.

MikesDuster, I want to stay with the 275/60/15, any taller on an A-body and it might start rubbing the rear quarters and may sit up too high, I think the 28's look perfect.

'71 Charger, 4:10's with 30-inch tall tires, 440, A727 TF Trans.

Yes, I can and do drive on the Freeway, but not often. It does tend to wear you out a bit.

I also have 4:10's in my '74 W200 Power Wagon pickup, with 33-inch tires, manual transmission, 360 engine, also Freeway Driven.

My '79 CJ5 Jeep, AMC 304 V8, manual Trans, 33-inch tires has 3:73 gears and is a very good compromise of acceleration performance and freeway driving.

What are your cam specs?

I had 2.76's behind my 493 with an MP509 cam and stock converter in a 4800 lb C-body.

With over 500 ft/lbs from 2000 it had no problem getting around town but it wasn't "happy" cruising where a 2.76 put it.

I put in a 2800 Turbo Action converter to cushion the 1100 RPM neutral drop on the drive line and a 3.23 SG and all is good now.

Kevin

Frankly the gears are not going to wear out the engine sooner then blowing it up at track so who cares! I run3.91-4.10s with 25 tall tires and have run 4.30s and 4.56s for close to four years and have driven them for hours at a time. If your cooling system is good and engine in tune a bit of 4000 will never hurt it I run LT tires with the 4.56s too much worry for nothing besides you won't get the tickets for speeding going 60-70mph on the interstate

Frankly the gears are not going to wear out the engine sooner then blowing it up at track so who cares! I run3.91-4.10s with 25 tall tires and have run 4.30s and 4.56s for close to four years and have driven them for hours at a time. If your cooling system is good and engine in tune a bit of 4000 will never hurt it I run LT tires with the 4.56s too much worry for nothing besides you won't get the tickets for speeding going 60-70mph on the interstate

I use 4.30's and run the 30 x 9 Hoosier radial slicks. I drive to the track on them and race on them. I turn about 3200 at 60 mph and dive it the 90 miles to Carlisle like that on Rt 83 and the PA Turnbike. I use a 9.5 Dynamic street/strip converter. It does not bother me at all on the highway as most cars ran 3.91's or more gear when I was a kid in the 60's as I remember riding in a friends brothers 69 Cuda 383 with 3.91's and short street tires about 25 or 26" tall. It seemed like he was turning 4000 rpm at 60 mph(just a guess as I was 14 when riding in it)and it seemed everyone with a hotrod or muscle car ran alot of gear and still ran the highway. So I guess thats why 3200 rpm at 60 dont bother me. In fact it sounds like the eng is just purring along at that rpm. Ron

I can see a gear swap from 3.55 to the 2's if you go on a lot of 2+ hour drives. Might want to try to go 2.5" exhaust after the mufflers to bumper to quiet it down. I have 3.55 with 275/60/15's on my sb demon I usually keep it at about 2,800rpm which is about 63mph, when I get above that speed the road and wind noise become more of a pain.

Paul, That would give me a headache lol, I'm not worried about my motor, it could handle a 250 shot of nitrous. I'm just worried about my annoyance level. I got real spoiled to my Mustang going 70 at 1900 rpm's.
I think tightening the converter some might be all it needs, if not I'll install some 3.23's.

Back calculate it.What's the max cruiser rpm you are comfortable with? What's your max cruise speed? What's your tire size or how many revolutions of the tire per mile?

With those three numbers you should be able to calculate it. Trick is that 60mph is one mile per minute. So revolutions for a tire to roll one mile become tire rpm at 60mph.

For example, 3000 rpm at 80 with 27" tall tire.

27 x pi /12 = 7.07 feet per revolution

5280 / 7.07 = 747 revolutions per mile

Turn ideal rpm at 80 into rpm at 60

(60 / 80) x 3000 = 2250 rpm at 60

calculate gear ratio 2250 / 747 = 3.01 That's optimum gear ratio assuming the car is either 4-speed or converter slips only a little bit. If converter slips 3% then multiply ideal gear ratio by 0.97, giving you 2.92 as the ideal ratio.
.
Now pick your closest factory gear ratio.

Done.

R.

I hated the 4.30s in the hot rod. They were fun for the first ten minutes. After that, they had to go.
I swapped them for a set of 3.23s at the Nats. Literally. I saw some guys looking at 4.30s in the swap meet. They had 3.23s in their car. I proposed a straight across swap with them doing the work.

I got up to speed on the highway, dropped the 833 into OD and smiled all the way home.

I miss the OD and plan on stuffing my 518 OD into the Imperial.

The highways around here are ~70mph almost constantly if you plan on getting anywhere, tollways push 80. Obviously you can go as slow as you want, but my biggest annoyance with 3.91s was the constant screaming of the engine just to maintain a reasonable speed...hence the double-overdrive 6spd that now resides in my garage.

If I kept it with a non-OD, I would have put 3.23s in it and putted along, I was done and over with running low gears on the street.

At 3,200rpm instead of 70, i'll be at 110! 70 at 2,000.

I'm running 4:86's with 275 50 15 tires..it's just a little wine..but fun..

I really have to reply to this as I am the member that bought the G/V from Frankenduster. Let me say right here that he is a stand up guy, fair and honest and I love his car. I have a 4,175lb convertible 66 Coronet with a 540" HEMI. 4.5" stroke, 246@ .050 I roller cam and 3.54 Dana. Torque is not a problem with this set up! Last fall, I drove the car almost 400 miles round trip to the Mid TN Mopar show in Lebanon TN from Chattanooga. Most of the trip was Interstate at 70+ MPH. 3,300 rpm with semi trucks on your bumper is NOT fun! The car had a 9.5" converter and would still "slip" 300 RPM going up a hill. With the G/V I installed a Hughes "2,800" 11" converter. Now 70 MPH is 2,500 RPM on the flat and level. It still gains 200-300 RPM on a hill. But it is SO much more pleasant to drive on a trip! In an hour drive, the noise, vibration etc. is VERY reduced. With the 640+ ft.lb. of torque, I should have sprung for the TCI "power adder" converter for $900 with a stall of 2,200 RPM but couldn't afford it at the time. The OD ratio ends up at 2.76 and the car is just a joy to drive @ 60-70 MPH. In short, if you have the torque, you just don't NEED deep gearing, I like my "rear end" just fine, don't you?

Yes I do, and she matches my car.

why not put a 518 in it?
I run 3:91 with a 440 in my cuda with 26" tall tire and 60 mph is about all I care to cruise the highway at. I'm thinking about a 518 swap over the winter.

Once you've driven modern muscle with a 5 or 6 speed you realize what your missing out on.

My '63 was built to do lots of street duty with 2800 stall and 3.55 gears and 275/60's. I had ran 3.23's in my '71 'Cuda but wanted to step it up a notch with the '63 build.

I'm going to throw a set of 2.76's that I have lying around just to see what it's like on the highway. If it does okay it might get the suregrip in that 3rd member!

With over 500 cubes I don't think they will be a problem...

"FrankenDuster I love that Charger! What RPM are you at when going 55 and 60?"

Thanks for the kind words!

My tach crapped out recently. It could be the fuse, I have just been too busy with work and another car project to tinker with it.
Its been a busy year. I changed the cam to the MP 528 Solid and switched from the 3.91s to the 3.55s. If I recall, I was at 2800-2900 at 65 mph. I have some 3.23s, but this 3.55 chunk has new gears and a rebuilt clutch type Power Lock diff. I don't commute with the car, so the gearing is a decent compromise for me.

I ran 4.56's in my tube chassis street Cuda with the biggest QTPro Hoosiers at the time. If I remember right it turned about 2700rpm at 55. Also ran 4.30's in my 62 Dart 330 with (I think) 28' Hoosiers. Those 2 cars where for wk end warrior street cruising though.

Edit: Now that I think about it, those 28's were more like 383man's 30's.

Now that I have my 70RR back on the road, 1st time since 1983. It's a Dana 3.54 4spd with 27" BFG's. Tach says about 2750 at 55. Calculator says it should be about 2400-2450. Car sounds like 2700-2800 to me, lol ...probably cause I'm getting used to these modern OD cars & trucks.

On the list for the A855 for longer Cruises/trips. Will make dew till I get the last few miner things fixed on this RR. Then I may do a Passon 4spd OD if he'll do a trade-in on the 5spd.

Hey...mickm I got her going!

It might be necessary to go to a bigger converter core to get the characteristics you want. I raced a 535 in a 3400 lb car with a stock 340 converter, which is 10 3/4 inch core. The stocker only lasted six passes but stalled to 3800 behind that motor with 906 heads. You should be able to get somewhere around 3000, to 3200 (maybe even 3400?)with a stock type configuration but modified guts to make it live. Then the 3.23 gears and tall tires won't make the converter slip too much. The bigger core simply has more leverage which helps reduce slip. I can relate to the rpm problem for long cruises. I even have a lockup trans, and 3.55 gears with 28.3 inch tall tires is still buzzing the motor more than I like. Funny, forty years ago it didn't seem so bad. Guys were running more gear on the street all the time, and driving freeways with them.

back "in the day", i ran 5.38's [ ] in my charger with m-50's on the street. 50 was just about all i cared to cruise at, but if somebody wanted to pass, that "fun gear" really woke up in a hurry !

My Challenger, when I got it, was 318/3.23/auto with smallish tires and most likely stock converter. It worked fine on the highway... 3.23 with a tight converter (bigger diameter as posted above) should work fine with a stroker also. I don't know how aggressive your cam is... that matters a lot for stall and acceleration but 3.23's, big tire and tight converter should work fine on the highway.

One car with 4.30s another with 4.56s and both spooled with a 28 inch tire and a vert that flashes to 5k and love them both.

The whole converter slippage deal is something that would really get under my skin. With the 5 speed and a 3.27 first gear 3.54 rear gears felt really perfect in my Savoy.
When I ran the 4 speed with a 2.65 first gear I needed to run a 4.56 gear to make the clutch survive.
Now I'm back to a street HEMI box with syncronizers instead of face-plate or pro-shift gears I'm still flipping over 3.54 or 4.10's.
Running down the highway at 3000 never bothered me and I know the engine doesn't mind in fact it really likes to cruise at 3000 and seems to really smooth out at 3100 and seems really happy right there.
Gus

I'd like to but I doubt it would be durable enough for a 500" MW engine. I don't really ever plan on racing this car but if I ever change my mind I don't want to have to worry about the transmission so much.

By the way guys, my cam is the 557 MP purpleshaft, for those of you that have asked.

Gus I think it has alot to do with the exhaust system, but road noise and stuff like that come in to play also. My car is great at 2400, fairly annoying at 2800 and over 3000 is miserable. I'm looking at quieter turbo mufflers, and maybe tailpipes.
Last night's the first time I really laid into this car for an 1/8 mile type pass and it is much quicker than I ever anticipated, I'm dying to get some aftermarket axles and drag radials and see what this thing can do but it may never happen as I don't want to put a roll bar in it.

I would think a stock diameter, moderately increased stall speed converter + 3.23 rear would work well for general use (but no converter expert). This would leave a little on the table for max effort acceleration and cruise well. The 500 MW should have plenty of torque once it wakes up starting around 2200 or 2300 with that cam and CID as a guess.

My 496 with Ed heads and .55" lift fast rate mechanical cam pulls well from 2000 or so (manual transmission).

3:91's and I hate em...cr8crshr/Bill

Thanks for all the info everyone, it has really helped point me in the right direction. I've decided to remove the 3.55's and install the 3.23's.
And I'm gonna remove the 9.5" Dynamic street/strip converter and get me a heavy duty 11"(maybe a Hughes?). I think that combo will make me plenty happy and will save the tons of money it would take me to buy an overdrive setup.
My MP 557 cam is very smooth even right off idle so if I can cruise down the highway at less than 2500 RPM's I'll be all set.

Late to the party, but I'll add: Car has a 9-1/2" converter. Been running 3.91's and 255/60's (27") for a few years. Last year I did the NWDT, drove it to a few hundred miles on the freeway. Not too bad; about 3150 at 65 MPH. This year I've gone to 4.10's. Street driven plenty. I dig the deep gears, but admit I'd love to add a gear-vendors OD.

"What gear ratio are you running without an overdrive?"
4.10 with 28"x12.5"x15" tires
Since the local track closed a few years ago, it's only driven on the street.

It may be difficult to find a decent 11" converter. Lenny at Ultimate Converter Concepts once said that 11" cores are drying up and nobody was making new ones, but this was about a year ago.

Mine runs 2900ish at 75 MPH. 3.23's with 28" tall 275/60/15 tires.

What stall is your converter? I'd change the gears first and see how the converter likes it before I would change it.

Kevin

Back in the day it was nothing to order a performance vehicle with 3.55 or 3.91 gears and drive the speed limit all day without a care in the world. Always figure with a normal diameter tire sizing that came on the car that with a 3.91 gear the engine would be turning very close to double the mile an hour. IE: 70MPH at 3500 RPM.

There's quite a few 11" converters in stock in my area.
Summit has a Heavy Duty 11" Hughes 2500 stall.

I had a 10" nitrous converter years ago that would literally bog down a 432" motor without nitrous, that thing was super tight. I just want something that doesn't quite feel as mushy on the highway as my good 9.5 converter and highway gears. My 9.5 would be a great converter for a 9 or 10 second street/strip car with 3.73 gears or more.

It's a 9.5" Dynamic, I haven't tested the flash on it as I haven't even had any sticky tires on the car yet, it's probably around 4000-4400 with my 500" motor. I'm gonna try the gears but I really think the 3.23's will make the converter slip more.

FWIW... I'm using a 3.90 gear with a 30.7" tall tire,I'll be turning 3000 rpm's at 70 mph.

It has been said several times... but I'll add a comment anyhow. A BB, especially stroker, will handle 3.23's and a nice big tight converter just fine. I think you will like the car a lot better set up that way.

Imo...im thinkn ur vert is prob not right.

I had a 9.5 ptc that had zero with 3.23s, 3.55s and 4.30s. Also had a 9 inch fairbanks that acted the same with the same gear sets. I do have a 9 inch ptc that started life as a TA J. It isnt as nice on the street.

Just dropped my gears back to 3.55 w 30 inch tires and 8 inch TA vert. Took a 150 mile trip yesterday. Honestly acted very nice. I was concerned it might be pretty mushy, but even on a long hills, wasnt bad.

I tried to read through everything but frankly I'm not a fast reader so I might have missed some stuff. You had mentioned early in the thread a number of times that when your convertor locked up...........I'm assuming you mean when it reached it lowest slip point and not actually that is was a lock up converter. The reason I bring that up that up is I know they made a lock up 727 in trucks for small blocks, not sure there was every a big block application or not (assuming again that with 500 cubes you are running a BB) but I think I remember from conversations in the past that it only realy requires the change of the input shaft, the converter and maybe the front pump to convert it to a lock up convertor. Sowould it be fisible to change your trans to untilize a lock up convertor? Does someone make one or can someone build one strong enough to hold your torque? I know some lock ups are solinode operated but do I remember some were locked by fluid pressure or centrifugal force or something. If that can be done you will loose the slipage and 3.55s will be fine with a 28 inch tire.

I run 3.91s in my AAR with 28 inch tires but a 4 speed and I'll hang it on about 3 grand and let it ride, it's soemwhere around 68-70 mph. I have driven it 1000 miles 1 way several times in the last couple of years.

I run 3.54s in my Coronet with 28 inch tires also a 4 speed and really don't have an issue keeping up with traffic but it actually sounds like it is working harder than the AAR. I'vedriven it 1000 miles 1 way once and several hundred miles 1 way a few times.

I run 3.23s in my Charger with 28 inch tires and a 727 and I have to pay attention or I'll be passing everything (might have to do with driving the other cars ). Strangely enough I haven't taken it over 100 miles one way but I think it is getting the 1000 mile trip this year.

I run 3.25s in my Comet with a 260 and a 2 speeds auto with 25.5 inch tires and it sounds like it's gonna grenade at 70+ mph but it hasn't yet. Numerous 500 and 1000 mile 1 way trips, many quarts of oil.

Those are the only ones I drive any distance that gears would matter.

This^^^^^

We're all spoiled these days driving numb and silent camry's and Accords that feel like driving a sewing machine. Theres nothing wrong with driving along at 3k RPM's. It just doesn't feel the same as your neutered family sedan. My opinion is: Thank god for that! Its WHY I have a HotRod.

What he said!

Everyone's different, I got spoiled to a 6 speed manual Cobra mustang with a Kenne Bell intercooled supercharger that would float down the highway at 1900 RPM's. Had nothing to do with a neutered family sedan lol. I like to enjoy new technology, just can't afford an overdrive right now. My eventual goal will be to drive down the highway at a comfortable level, run a 10.90 and drive home, I already have the horsepower. High RPM on the highway is annoying to me, but not to everybody, and I've had some 9 sec cars.

I don't think anything's wrong with my 9.5, I'm just being picky, I've talked to Dynamic, it's setup as tight as they can make it going by the serial number and it is not slipping excessively, I just know that it would be more enjoyable for me to drive if the RPM's were lower.

I'll try the 3.23's first, if that's not quite enough I'll stick a tight converter in it.
Thanks for all the input guys!!

My Charger has 4.10:1 Strange 60 with spool and a tight 9" converter from Ultimate. The converter is so tight you would think it was a stock 11" converter till you punch the throttle then it flashes to 5,000 rpm. Really don't notice any slippage under normal light throttle driving.

I've always heard good things about Ultimate converters, but it would most likely slip a little bit if you put some 3.23 gears in there.

I switched from 3.55's to 3.23's years ago and never looked back. When I'm on the highway, I want to be able to keep up with the traffic flow (generally 70 to 80 MPH around here) without excessively high RPMs.

I wonder how many guys cars I could take, add some good sound deadener to the floor, firewall and trunk, unhook the tach and tell them I put in an overdrive! Seeing the number on the tach is what does it for most of us.

And tailpipes!

I agree the noise is what wares on you. I had a 79 trans am with a 4 speed 3.23. It was nice on the highway. Plesent on a trip. I traded it in on 1979 corvette l82 4 speed with 3.73's. It was fun on the back roads but not half as good on the road as the trans am. Before the trans am I had 1970 442 olds w30 with auto and 3.23 it was factory air car. It was also great road car. I would do some insulating and add out the back turn down tailpipes. I would use 2.5 tailpipes mandrel bent. The exhaust has cooled enough by the time it's made its way through the mufflers for the 2.5 tails not to hurt you much. The F. A. S. T cars do it through a full 2.5. That along with the 3.23 I believe will fix you if your converter is tight enough.

My humpster has a 3.15 ratio with a 27.5" tall tire. It's happy at 60, 65.
It'll actually get mid-teens for mileage if you keep it around that speed. Running 70, 75 will get you there quicker but will slurp up the fuel in no time.

My Gremlin has a 3.08 rear and no overdrive (yet!). The little half-dozen is generally buzzin' around 2,500 out on the highway around 60. That car is the most fun to drive. At 60, it's still got plenty of go left. If you need to pass, just leave it in 3rd, and walk on it. It just wakes up and goes around whatever you wanted to pass.

Love that little six!

This.

Fix the exhaust first. The 2 1/2 tails will be quieter and might actually make as much or more power as 3". If there is room you could add some straight thru bullets in the tailpipes to make it even quieter and help eliminate possible drone problems.

If you want to try some converters I have 11" out of a 69 Superbee and a never been used 10" Fairbanks that is old enough that it was probably built by Lupo before he started Dynamic.

Thanks GoMango, I sent you a PM.

Thats just how my 9.5 dynamic converter works for me. I never notice any slipping or high rpm cruising. At the track when I hit it the flash is right about 4200 what I wanted. Its their 9.5 street/strip converter and I have had in in my 63 since 2006. I can cruise in third at 2000 rpm all day and it sounds normal to me. Its never ran hot or gave any trouble and I drive it alot.
I also do understand how eng noise and rpm can trick people as I remember all the complaints we used to get at the dealer when people said the trans was not shifting into third because of the noise from the fan clutch. And when the fan clutch did come back on it really sounded different even though nothing changed in the eng rpm. Ron

I currently use 4.10s and short tires 25 inch tall on the 360 I have run for years 4.30s or even 4.56s with 28 tall tires Helps keep the engine cleaned out after a lot of very short trips Lowest I have run now is 3.91s do you get passed on interstate Yes but the cops will not be bothering you at 60-65 mph. My one car is B-3 and it does stick out on the road

This is exactly 100% correct. Unhook the tach. That engine is loving that RPM range. It's ain't hurting a thing.

My car has 4.56's and 27.5 tires. I drive it down the FW at 70 and it turns....well I'm not exactly sure because I don't care. I'd say it's 3800. Some day I'll look.

I've been doing this since 1981 when my first DD street car got 4.56's. The gears paid for themselves in one weekend. Hell, I may go to 4.88's in the future.

LOL, I already know there's nothing wrong with my car or converter, like I've already mentioned many times, it's just personal preference. Tailpipes and sound deadeners don't fix RPM, just covers it up.
I drive this thing alot and I do not enjoy high RPM with a Prius blowing by me, I want to have alot of gear left in case I need to show someone these taillights.