Actually there are several questions to this post.

Since this is my 1st Mopar with a 383/4bbl to be exact (no tach yet) in a stock 64 Fury I'm wondering what to expect for a safe or typical RPM redline. 5000 was it for stock small block chevy's I grew up with and I'm figuring 5000 is about it for a stock 383 as well. Is this right?

I was thinking of changing the 3.23 rearend for a lower ratio to add some zip but after reading several threads on this forum I think I'm going about it all wrong. Looks like I should be trying to increase the HP and Torq before messing with the rearend ratios.

Any suggestions for bolt on items that will increase the power and what kind of increases can I expect. I don't want to break this engine either as it is the original to the car, but I also starting to question the real value of that too. Seems nobody wants stock and 440/426's seem to be the big draw on these cars.

Thanks,

Butch

the stock 383 cam is all done by 5500. the manifold wont do anything above that either . you might get a little more rpm out of it but power will be dropping. change the cam and intake and put on headers and good exhaust and youll see the redline go up. maybe rejet the carb too. as far as the gearing goes, the 323 is not really a performance ratio so if it was me i would go to at least 355s. you could modify the engine 1st then if your happy with it leave the gears alone.
if you pick the right cam, intake, headers, you could see a 30 or 40 hp increase.

Some of my stock 383s were stronger than others, sometimes by a margin large enough to be baffling.
Usually they run out of pull around 5200-5500 RPM.
For a street car with 3.23s, I'd tweak it for torque.
A really sharp tuneup, good dual exhaust with H or X pipe, better ignition, Eddy AVS-style carb, and 1.6 rockers & better valve springs would be my first mods.
After that maybe a more modern cam profile and either HP exhaust manifolds or smallish headers, but it won't look so stock anymore.
If you plan on enjoying the power, the 10" brakes aren't really up to the task, and I'd put some swaybars on it.

Assuming that this is an original untouched engine valve spring tension could be anything from good to poor in which case anything from 5000- 5800 rpm is possible. Early heads like yours have some serious drawbacks. First of all if you intend to put any real mileage on it,
hardened exhaust valve seats should be installed. While you're at it you may as well do a proper three angle valve job and take a .010-.020 truing cut on the block surface of the heads. A bowl port would help a lot as well. The problem with all this is that the cost is such especially after probably having to repair/replace worn guides that you could buy new aluminum heads that flow better for very little more money.
If you want to roll the dice on how long the valve seats will hold up, buy a good set of headers and an RPM intake and top it with a 3310 Holley [750 cfm, vac. sec. ]. Two safe cam choices for a basically stock engine would be the 272 MP purple shaft or a Comp XE268H along with fresh valve springs. You SHOULD always check piston to valve clearance and retainer to guide clearance as well as coil bind with any cam change, but these cams are mild enough that you probably won't have any problems. These cams will work with your stock torque converter although they may pull a little in gear at a stop. If you plan to hammer it a lot a Hemi pan and pickup would be a good idea as well.
If you can afford it the best solution is to yank the original engine and store it and build a good 451 low deck. It will look like a 383, but run much better.
You have a lot of choices, it just comes down to how much speed you want and how many cubic dollars you have to spend.

Headers and intake I would do either way. But cam and rear end gears have to work together. If you go with numerically higher rear gears say 3.73 or 3.91 or 4.10 you can get away with a lot more cam than with your stock 3.23's. But it all depends on what you want out of the car(and how high of a cruising rpm on the highway you can stand!).

But I agree w/ the above post, heads at this age often need help. If your valve springs are old and weak your engine may not even rev above 4500-5000rpm.

What cam do you even have? If it is a stock then a cam change is pretty a pretty good for a street car.

A gear change will only get the car to shift gears sooner at the track and not really do anything for you if you don't run a large cam.

It may feel faster if that is what you want, but members have posted in the past that a gear change resulted in less than a tenth change in ET for a mild combo. We are talking a 3.23 to a 3.91, not really worth it unless you are going to get real agressive on a cam. Then the gear gets more important.

If you are asking what the bottom end will take, this ain't no Chevy. It should be good to 6000 unless it is worn out, then all bets are off. The cam/springs will limit how high you can turn it though.

Great responses and very helpful. This is supposed to be a bone stock 383 and I have no reason to doubt it. Bought it represented to have 39000 miles which was on the Title (I know big deal) but every part of the car looks it. Engine revs surprisingly quick up and down which also supports the low mileage claim. But, regardless, its 45 years old and the motor isn't a spring chicken anymore. Absolutely stock under the hood including the foil heat barrier underneath the intake.

This will always be a street cruiser and not a race car while I own it but like everyone else I like to punch it and feel the power. I expect one of these days I'll be locking horns with one of the little imports on the street and would like to have a presentable showing for the old gal.

But, the old saw seems to be just as true today as it was 40 years ago. "Speed cost money--how fast do you wanna go?"

Love to put a stroker, upgraded 4 speed A/T trans and converter with a 65-67 suregrip and higher gears, but that's another $15-20k by the time the brakes, suspension and other items are upgraded to match the power. Not sure I can justify that as I don't have that many years of driving this type car left in me and what I see the modified 64's bringing (or not bringing) these days is pretty sad. Guys are lucky to get half their money back.

So, I GUess I'll take this a little at a time and see where it leads me. I'll change out the intake, carb, maybe headers or HP manifolds (by the way are these manifolds almost as good as headers) and definitely some suspension updates. I sure don't remember the 60's cars driving so loose and sloppy. Kinda like driving a boat. I've added HD shocks so hopefully some swaybars and better tires will help.

I just know one thing leads to another and it's hard to just do one upgrade without wanting or having to do several others. So, I guess we're off to see the wizard!

Any other recommendations are greatly appreciated especially on which mods to do 1st.

Butch

I don't think they had the HP cam back in those days so that will be a real mild stick, going to limit what you can do.

The steering box may be in need of an adjustment.

Some people still like the 383

Factory (dual plane) intake, 600 carb, 1 3/4 headers and 4:10 gears and redline at your best shift point, 5000-5500. Also, a Mopar electronic ignition and Blaster coil with a plug cap set at 40.

I like the 383 if only because they used to beat me in the 60's when I was driving 327 chevy's.

I know the new rule is bigger is better but I can't believe a 383 can't be made to run strong and compete with the other big blocks without breaking the bank.

Butch

Regarding the lossey/gossey feel. The last thing you need is a strong engine [ ie. fast car ], and a worn out suspension and drum brakes. You can swap 70's-80's disk brakes on to the front and putting a '65 or newer rear end with flanged axles couldn't hurt although it's not really necessary at this time. Chances are good that the suspension bushings front and rear are shot from age. Bushings are relatively cheap and except for the LCA are easy to replace. Use either Moog heavy duty or poly. Personally I use poly for the UCA and the rear shackles and Moog for the LCA and strut rods and the front spring eyes. Strut rods bushings are very important since they maintain toe in. OK, the others do too, but they have a LOT to do with it. I guess I've spent enough of your money for now, good luck.

http://www.moparmusclemagazine.com/techarticles/155_0209_resto/

is a great article showing step by step dyno work on a 383 from stock to more radical. Your stock heads aren't going to flow what 906's will but it's still an instructive article.

Call Summit order their 488 cam, find a used Holley SD intake, 750Dp carb, headers and an electronic ing kit. Set your timing at 38* at 2400 rpm, get a set of 3.91's and go have fun. Should spin to 5800 easy.

If it is log manifold on those heads its all done by 5000 Period The HP will go 5800 but that was 68 up but power wise the 325 horse 383 was done power wise by 4500 and really doubt 325 horse 383 made anywhere near that number. The HP yes but the older ones in the 66 chargers etc were just not that fast

Hey, don't worry about spending my money. The car needs to ride and handle right before adding more power. I wonder if replacing bushings is the way to go or should I just get a front end kit from Moog. I've seen prices on the front suspension kits and they run around $500-600. Don't know what the bushings only would cost.

Butch

around 5000...give or take a bit...I run a 498 stroker(440) with a real nasty cam and 5500 is My redline...give or take a bit....

Thanks Furious70,

That's a very interesting article and some very impressive information. 450hp out of a 383 with just a change of cam, intake, carb and headers is pretty remarkable. That's the kind of performance I was hoping this engine could produce and is plenty of HP for me on the street. I hope the stock lower end can handle the increased power.

Butch

You should have no problem with that bottom end. A new oil pump would be nice ,but usually not necessary .

Stock bottom end 383 Laying it down at very high rev (FF past the Beaumont)

I spin my stock bottom 383 to 6400. no issues. 383's are pretty stout. remember that they have a forged crank and the same webbing / oiling / architecture as 440's and Hemi's, only with a smaller 3.38" stroke that does not tax this hardware nearly as hard as the RB's 3.75 stroke. I've always felt that the 383 was about as durable a workhorse as ever came out of an American auto maker.

I saw some guys try to blow up a worn out 383 by putting a brick on the gas pedal trans in neutral, well it reved to 6000 for about 10 minutes and just sort of lost power and died, later when we pulled it apart the only damage we found was where the valves had nicked the pistons and slightly bent the valves just enough it would not run.

I once missed 2nd getting on it hard and it sure sounded like I hit 6000 rpm!

Go with the tried and true Comp Cams Xtreme energy 268 series (maybe maybe the # below the 268). Do a search and see the phenominal performance from this relatively mild cam. That cam- new valve springs, iron intake, OEM carb, headers, electronic conversion kit (Pertronics) Trans go or B&M shift improver kit- All the above is not expensive and is the way it was done back in the day when we could get good running, sound-used 340s, 383s and 440s. Sounds like fun. Id love to have a sound factory HP motor that did not require a full rebuild.

Great! I'm really excited about this. I've always felt the 383 was pretty much bullet-proof kinda like the old Chevy 283 and 327's. Very forgiving engines.

Does it make any difference that this is a 1964 vintage 383 HP engine as far as the bottom end strength? Does it still have the forged crank?

Since the valve train and upper end seems to be the limiting link in making power would I be better off to change out the stock heads for something with bigger valves, etc, etc or just update these stock heads with better rockers, hardened seats, etc.etc?

What would be the best aftermarket manifold/carb combo to use now with the stock cam ....knowing that someday it might have to be changed out if the cam, heads and other items are updated?

I remember "in the day" Carter AFB's were not bad carbs. Is the Edelbrock replacement much better or should I go to a Holley? Will the Holley retain the fuel any better than the current AFB that evaporates in a few days?

Sorry, but the more answers I get the more questions I have and I'm getting pumped up on this.

What first seemed a little overwhelming with high PITA factor is starting to sound like fun.

Butch

Don't compare a BBD to a sbc..Its like an apple to a steaming pile of cow dung Anyways.....
The bottom end is good, forged crank, rods, and tough cast pistons. The old recommendation is not too much over 6500 or the pistons may seperate. (I don't know if I buy that, never seen or heard of a 383 or 440 piston that split..)
Theres no point in worrying about heads if you have the stock cam. I would use either the 915's, 516(w/big valve) or 906s. The stock valve train should be good, unless you get wilder with the cam. Personally ,I like bigger cams, torque gets you going, but its always more fun at the topend when your horsepower kicks in and you drive by the putz in the 440 car that was just bragging about how much torque he makes...All you need is good gears and convertor

The 64 has the small valve closed chamber heads. If you replace the heads you need to pay attention to the chamber size. 84cc Edelbrock heads would be a good choice.
Pistons are the only thing you need to consider changing in the bottom end and you can put that off for later if you want.

If it turns out you need to do any amount of work to the heads other than put new springs in, you should probably just buy other heads. As was said, the early, small valve heads aren't really worth putting money into.

I would agree, the article ends up with more cam than you'd want, but the engine was making 400hp/430tq with the stock cam and all the other bolt ons.

For a respectable cruiser and low cost: If it were me I'd use the XE262H Comp Cam, headers and a 650 Holley carb; stay with the 3.23 gears and run the Hughes Street Master 2500 (will flash to about 2,500 RPM's) torque converter. I'd have the heads worked over with 2.08/1.74 three angle valve job, or purchase some heads off of a newer engine from say a 1969 to 1971. The XE262H cam is going to give up about 5 to 10 ponies compared to the XE268H cam, but will gain 5 to 10 pounds of torque over the 268. It's a trade off...more torque or horse power. Run a 2 1/4 inch exhaust system with 1 3/4 inch headers. I went with the 262 cam in my 383.

PS, I shift at 5,700 RPM's.

Thanks again everybody. Yep, 400 horses without touching the cam is very respectable.....plenty of HP for me (at least now) and it sound like most of what I bolt on now can remain if I add the right cam and heads later.

Butch

My 56k original mile 69 383 4 bbl with hyd. cam ... and a timing chain that was ready to jump a tooth or 3 ... goes into valve float at about 6500 rpm , I was shifting it at 6200 at the PS drags a couple years ago ...

440. Stops pulling at 4800 per Chasis Dyno. rev Limiter at 5300 and gets bumped often.