What were they thinking? 55mph spinning at 3,500 rpms. lol

Stop light wars

Ii ran my 64 Polara with 68 340 in it from Ne to Ca back in 1972. No speedo so i ran at 3200 RPM all the way thinking it had 3;23's. with G70-14's on the back. 1 candelpower headlights to boot LOL. Later found out it had 2;76's. Calculated speed ~95 MPH. Oh and the car had all new suspension brakes tires etc. LOL (NOT)

Acceleration, rapid acceleration: devil: my friend

"What were they thinking? 55mph spinning at 3,500 rpms. lol"

I've got 4.10s in the Dana of the Dodge. I take it across town - but not across the county!

3.55 is my favorite street gear, though. 2.45 in the Magnums with a crappy lock-up converter and I could cruise the interstates comfortably at 90.

Back in '69 I ordered my first car a '69 Road Runner with 3.91 Suregrip and a 727. A few months later my friend bought a '69 Road Runner, 4-speed with 3.23 open rear. Somehow being young and nothing to do we decided to drive from southwest PA to Atlantic City just for the weekend with a his brother and a couple of friends. We got on the PA Turnpike with me leading the way and his brother in my RR riding shotgun and not too far down the pike I'm getting low on gas quickly so I pull into the first service plaza and his brother jumps out of my RR to go flag his brother down who was not keeping up and faded way back out of sight. Finally his brother comes into sight and pulls into the service plaza, pulls up alongside of my RR at the pump and screams "[censored] ARE YOU DOING DRIVING SO DAMN FAST FOR?:" I said I've been doing 65 the entire time, to which his brother, my passenger, says "yep he never went over 65 but with the 3.91 rear it sounded like we were doing a 100". His brother then says "YOU WERE DOING A HUNDRED AND SOMETIMES OVER THAT!" His brother and I laughed and kind of gave him the look and finished filling up with 260 got into my RR and I looked at the speedometer and said hey check this out. My new Road Runner's speedometer needle was stuck straight up at 65 MPH at a stand still. Turns out the plexiglass was bowed or warped and was making contact with the needle and when I got back it was replaced under warranty. All it took during that weekend trip to AC was to tap the plexiglass anytime I was returning to less than 65 or whenever I was above 65 MPH. Was a PIA but had to be done. I think I went past a PA State Trooper at or over 100 MPH right before that service plaza and got real lucky he was on the other side and moving. Check out where 65 MPH is on a Mopar or RR speedometer, yep almost straight up. This was back in 2003 when I drove my before restoration '68 Road Runner (3.23 Suregrip) from El Paso, TX to Northern Ohio, great times.

Mike

Another 4.10 cross country story:

Rotting down in a field near here is the shell of a '71 Hemi 4sp RR with 4.10s. The car came from the Pacific north west (not sure exactly where) and was driven here in the early '70s by the young man who came here to go to Southern Illinois University. That is about 2,000 miles give or take. I talked to the guy many years ago. He said it absolutely ate him up in gas and in oil. So he sold it as soon as he could when he got here. Of all things, a cop in a nearby town bought it. I talked to him too about the car and his experiences with it.

Did I mention the trailer hitch on it to tow the U-Haul trailer? The hitch is still on the car today. The car's ultimate fate is just about a sin to me.

Its not that bad but it could be better lol. Every September if I am lucky my Dad and I do drag week in my mid 10 second 68 Barracuda. 4.10s, 4800 converter, hours and hours through cornfields and interstate wherever they take us. I always talk about an overdrive but never do it, it all works just fine the way it is. Usually we do lots of two lane stuff but sometimes they stick us on the interstate for a few hours.

You need taller tires. Lol I run 28" on my Cuda with a 4:10 and only turn 2778 @ 55 and 3536 @ 70. My factory stock 65 vet with 3:36 gears turns 3,000 @ 70 so it's only 536 more.

I have always liked 3.91s and have them in the Cuda. But many of my buddies have late model cars and want to hop on the interstate and run with traffic to a destination. So I converted a 518. WOW! What a difference. 75mph on the hiway and the engine sounds very relaxed. Didn't help the gas mileage much, but wasn't expecting it to.

No way would I ever go back to only 3 gears. The only down side is probably the weight. Man, that thing's heavy.

I have 4:11's in my 70 Charger, 4:10's in my 70 Challenger and 4:88's in my 70 Roached Runner. Hell, even my 12' Challenger has 3:91's.

Same reason for converting to OD myself. Car had a 4.10 and expressway driving was not fun. People did it though.

Car has a 3.54 now with the same OD. Nice being able to keep up with interstate traffic.

Mike, that's a great sunset picture over the hood!!

Clark- I'm at 4.30's with a 295/65/15, am right there with you for engine speed, it's cheeching along at 3500 rpm @ 70. Could your megasquirt control a Gear Vendors? I'm at the point of buying driveline parts and the idea of installing an OD is really tempting. Besides the initial cost it doesn't seem like there are any drawbacks with a GV unit.

Related to the gearing discussion:

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Do the math on the Gear Vendors OD before you pull the trigger. It is not enough OD ratio for some guys. The 518s have an OD ration of .69:1. The GV has .78:1.

You can do some calculations here; http://www.wallaceracing.com/Calculators.htm

Agreed, I've seen a few people complain that it isn't a ton of overdrive. It isn't like a 0.5 OD like on a T56.

It would be cool to build a lockup style 727 with a GV or a 518, but I don't know how much power they can take. It seems that past 1000-ish it is not common to stick with a Mopar based trans.

Like most things, the rear gear really depends on the combination.
My Hemi 4-speed RR had 4.10s & 28" tire, and with a fairly big cam/headers, it was happy at 3500 or so on the highway.
Get into the throttle, or for more fun drop down a gear & get the 2nd carb involved, and it'd rocket to triple digits.
Ate a lot of fuel but that wasn't a concern. Seemed it needed at least the 4.10s for low-speed driving.
One of my basically-stock 383/4-speed RRs had 3.91s when I got it, but seemed too busy; 3.23s calmed that down.
What it seems to want is more ratio at lower speeds, though.
For me, if applied to those cars, the Passon 5-speed is appealing for the ratios, but the price, delivery & issues spoil that option.
Added a GV to my 454 Dually with 4.10s many years ago, and it made the truck much better on the highway, driving or towing, and it's been bulletproof.
At 65-70 MPH, it's right in its peak torque - light throttle @ 2500-2800 RPM is a sweet spot - and the MPG is better by 30% than without the GV.
My Mustang (4.6/5-speed) with 2.73s has a nice ratio spread, and is great on the Interstate - 80MPH is roundabout 2000 RPM or so, 30 MPG with AC on.
That's what it's best at, so I've resisted the urge to swap in more gear to crutch the relatively weak power - it's the Interstate tool.
As far as power capacity, a lot of the Drag Week guys are using the GV.
Bottom line, it's all about having the engine in the RPM range that's best for the combination & usage.

Thanks! I-25 North between El Paso, TX and Albuquerque, NM just cruising on the way home to Ohio

back in the day i ran 4:30's ,56's, 88's daily and 5;13's somewhat .
have had 4;10's in my 38 for 30+ years and have been pondering an OD or cam and gear change

My Dart has 4.10 with a 28' tall tire, it turns 2900 or so at 55. A guy I know drove his 66 Chevelle from W. KY to Texas and back in the 70's. The car had a 396, four speed and 4.88 gears.

For me the cost of the GV isn't worth it and it adds wieght which is the last thing my car needs. Locally when I drive the car I am seldom on highways and such, I either drive to the track or just cruise around town. My engine likes to run at 3000-3500RPM it is smooth and quiet at those speeds, so if I got a GV I would just drive faster which would be nice, but for $2000+ ill stay in the slow lane.

You need some taller back tires

Years ago I drove my 71 Challenger to Carlisle with 4:30 gears

At the time it had the Blower on it , stopped every 100 miles to fill it up

was with a group of friends and they thought they would blast past me coming down RT 81 , they figured I couldn't or wouldn't keep up

The looks on their faces when I did pass them at about 100 mph with the blower screaming and the engine wound up

Ditto on the taller tires. Back in the days, my 70 Challenger was running a 4.10 dana w/auto. Was my daily drive for two years, travelling every weekend from MD to VA on I-95; wasn't too bad. Had L70s x 15 tires in rear (yes, L70s for those old enough to remember; Hijackers were maxed out at 150 psi to prevent occasional fender rubs). The other 70 had a 4.56 dana (4-sp w/L60s x 15) which was almost unbearable to drive, again on I-95. Had to leave around 1:00am to prevent any traffic tie-ups and truckers from running me over in the slow lane. Drove the minimum 45 mph speed limit the majority of the time, on occasion up to 55. Took about ~4-5 vice ~2.5 hrs for the other Challenger. As someone previously mentioned, stop-light-to-stop light was the fun part with the 4.56's.

i ran 5.38 gears in my charger for a while.
they were fun, but that eventually wore off and i swapped to 3.91's.
the car was as fast with those, and had more mph at the stripe to boot. imagine that.

I run 4.56 gears on a 29” tire. Needless to say, I don’t leave town.

If you use the right parts a 727 based trans will be fine at 1000HP, look at the Cummins powered rams making more HP than that , and the torque is even more than a gas engine . If you build the OD unit to Diesel specs you should be fine, the issue you may have is getting a lockup performance convertor for a gas engine in the stall you want? But they are making them for turbo 400 racers so there must be something available ?

Its not 1980 any more.... set your rods and mains at .003, deep pan and good oil, optimized cooling system and hammer down. The most friendly gear I drive is a 4:30 the better is 4:56 and its happy in the 5-8k area. Nothing better then running 65mph and someone thinks your spent till you pull it down one and then they know the real truth.

I think back in the day the mostly stock bottom enders would of benefited from a bit more bearing clearance and better rod bolts.

Some have got complacent just cruising and cant/wont even run off a stop light which for some isnt a bad thing considering stock or just above stock cant muster a win over some modern V6s.

In the 80-90-s old iron still ruled over anything new.... no longer true.

My black one has 3.54s and is fine on the hiway even at 75 mph , but it is up there for RPMs . Its a hemi auto

My yellow has 3.91s and is a LOT more fun around town . but is screaming at me at anything over 65-70 mph its a 383 auto

Both have a 27inch tall tire

I have run 4.10 for yrs (30) in a 416 sm blk been 20 miles to 2000 miles & just under 2700 RPM but i run a 32 tall tire, keeps it at the 2700 RPM . Just like to get out on the interstate or old country roads people don.t expect to see our old cars there. To me it,s all about the smiles per mile

I was talking w/ a mechanic,and was told it's a real PITA to put a new ring and pinion in a Dana. Looks like I'm sticking w/ the 4.10s

I would guess he didn't have the tools needed. Ive done it on stands but a lift would make life easy.

Same here. It's not too bad with the correct tools. I have the T&D installation tool kit. It includes all the extensions and pieces for all the popular rear ends. I put 4:10's in my Dana in my Challenger.

Find a new mechanic.

Most vehicles have integral rear gears. If the 'mechanic' said the Dana 60 is hard to set-up then he must not be much of a differential guy.

look for a "rear end" guy.................[i couldn't resist. ]

Just for the record your honor, I said A mechanic, not MY mechanic! lol

Yep this is the way to go really. Convert the trans. As much as I love the bullet proof 727, if you really wanna have the best of both worlds....

Swapped in a 518 and could never EVER go back to a 727.
3:73 gears, only 2500 RPM at 80

Agreed , the guy either has never done one or just doesn't want to make money unless it's a job he can charge book time for that he can do for less. I bought a case spreader just so I can do them myself .

Mark swap a ford 9" in and I bet the guys answer will change ...

So is a ten bolt and twelve bolt GM rear end, any non drop out rear end has to have the gears set up in the rear end housing, I bought the tools, bearing puller and pinion depth tools to do my own. I take the housing out of the car and set the new gears up in the shop so I can keep it clean, warm or cool and take my time doing it correctly. I did make some set up bearings also, which helps a bunch on setting the rear ends up

4.56 in my street car currently. Tons of fun. And gas.

HAHAHAHAHAHAHAHA !!!!!!!!!!!!!!!!!!!!!!