You think I'd be better off with a 350 or a 383? I mean a 350 will turn a little tighter and should have more punch, but a 383 will have more HP (less RPM range tho).

 

it should also have a code around the differential

 

well do you plan on actually circle track or road racing it?

i still think you will be happier with a 383 since it will probably be more of a street car

 

A 383 is just a 350 with a longer stroke,it'll have more of everything and nearly as high revs,enough that you'll never lack for enough.
Whatever rpms the 350 can do that the 383 can't the 383 more than makes up for in seat of the pants power when you punch the gas pedal.

The M22 trans is stronger than the M20 or M21,the gears are more straight cut to carry a heavier load and are close ratio,quite a strong tranny.
Not many out there original but many Muncies were converted to M22 gear sets so you can only tell for sure by looking at the gears through the inspection cover.
They make a distinct whine going down the road as the straight cut gears are pretty noisy.
Here is some good ID info and will help you tell if you have a Muncie,Saginaw,or BW T-10 and if it's a Muncie which one you have.
A car that old may have been through a few trannys and or rebuilds.
http://www.camaros.org/trans.shtml
http://www.yearone.com/updatedsingle...nfo/muncie.asp
http://www.muncietrans.com/munice4.shtml


The shallower mesh angle of the M22 causes a "whine" noise in 1st, 2nd, and 3rd gears and the sound is the reason for the popular nickname for this transmission, the "Rockcrusher." The lower angle increases the load carrying capacity of the gears at the expense of the increased noise. The reason for absence of the noise in 4th gear is that 4th is a direct output from the input (1:1 ratio), and there are no significant gears involved.

The rear end should be a 12 bolt if the car is a Z28 or SS but again who knows how many rear ends have been swapped in or rebuilt over 30+ years.
The numbers on the housing may no longer be the gears inside.
10 or 12 bolt you'll have to open it up to get an accurate gear ratio.
Count the teeth on both the ring and pinion gears,divide the pinion into the ring and you have the ratio.
You can come close buy turning the wheel a full revolution and counting how many times the drive line turns,about 3 1/2 turns for one wheel revolution you probably have 3.55 gears,about 3 3/4 turns likely 3.73,a little over 4 turns 4.10's or 4.11's and so on.
If you get both wheels off the ground and rotate one wheel with a posi rear the other wheel will spin with it the same direction.
An open non posi rear the other wheel will spin the opposite direction so it's easy to tell that aspect.

 

Whatever you decide you need to decide how far you want to take the project. Before you go forward you also need to determine answers to all the above questions. Once you're sure of what tranny and rearend you have, plus the axle ratio, then you can determine what engine it will handle, and how much HP you should be looking at.
After you've determined all the factors, then decide if you want to build something that works with your present setup, or go bigger, and have the domino effect where everything after the engine needs to be built up too.
Of course you can just dump a high HP engine into it, and then see how it holds up. That's learning the hard way, but if it's not your daily driver it's not the end of the world. I went through this process most of my younger years, and it's a learning experience that can be strung out over a long time, and a bit of cash.
Regardless of what your setup is, you should be able to handle something in the 350hp-400hp with any good 4spd, and a posi rearend. Maybe a bit more if you're not "testing" it a lot.

 

Reminds me of when I first dumped the built 427 in my '69,it had a one wheel go 3.08 10 bolt and a wide ratio T-10 4spd.
I never blew the rear end but I went through a few u-joints and ate up some tires.
Damn thing would do 70mph in first gear lol,I could smoke one tire for about a mile.

 

Well it would be more of a road race type car although I dont really plan on racing it much. (Besides those unexpected events at a stop sign )

 

Well I know for a fact it's a posi because I asked the guy I bought it from (a family friend) and he told me that it was a Muncie 4 speed with a posi rear end. He just didnt know what gears were in it or whether it was a 10 bolt or 12 bolt. Also, it's possible that it actually has the original trans/rear end in it as the car has been sitting about half of its life, but who knows for sure until I pull it apart and look.

Thanks for all the good info! That'll definitely help when I go to find out what it is.

 

Good points. I think I'll probably take a look and see what it is as that would probably save me some time and money in the long run. And the other thing that'll determine what I go with for an engine, trans, and rear end is my budget.

 

Damn. Hope my car will do the same thing when it's done lol.