Rear differential OAW 356 E1 I believe is a 3.08 gear ratio in my 1976 Corvette. I would like to get more low end tourk. I hear 4.11 is to low and that 3.55 is a good choice what do you suggest? The vet has 383 stroker and m20 4 speed Muncie I want to use car locally around town and do burn outs. Let me know if you have any suggestions, thanks

 

welcome

 

Welcome, moved you here out of introductions for help related questions

 

I have 3.73's and I want to move up to 4.10 someday. But I think for a four speed the 3.73's work great, but I wouldn't take it on the freeway/hwy for long trips until I got overdrive. Around town is great fun though.

 

A five speed with a deep low gear and O/D would be best.

JIM

 

The OA code is indeed a 3:08. The W indicates the assembly plant (Warren, MI).

3.73 is a very popular ratio, 3.55 is close.

Some things to consider:

If your differential is the original, it probably has badly worn axles. This is common so don’t be surprised. On the positive side, you have the 3rd gen posi carrier with 17 tooth spiders.

Good quality replacement gears are very difficult to come by today. Do your homework before you source any replacements.

Rebuilding these differentials properly requires a lot of knowledge. Most “rebuilders” just do the minimum needed to get them out the door. Be very cautious about swapping the whole differential as you won’t know what is inside the replacement from a “rebuilder”. @GTR1999 on this forum is the authority on these. Read his posts and heed the advice.

Your Muncie is a good transmission but upgrading to a 5 speed (Tremec TKO or TKX) will ensure you won’t blow it up while doing burnouts. That said, you also need to consider upgrading the inner axles to 30 splines and the outer axles to 31 splines.

As you can see, the pitfalls of adding power up front results in lots of exposure to failures south of the flywheel. You really have to think it carefully through and assess risk/reward for each decision.

 

If you can't do burnouts with your current setup, check your timing.

 

My 68 big block 4 speed has a 370 rear gear but the speed limits around my area don't exceed 55mph so it's ok. If you're only cruising around and no long 65-75 mph highway journeys it'll be alright

 

What ever gear ratio you choose, you shouldn't have any trouble spinning street tires all the way down the road with a 383.
I run a warmed up 350 manual with a 3.36 gear and spinning the tires is absolutely no issue. Replacing half shaft U joints does get old however! And if you twist one off! WOW ! Complete new rear quarter panel time.

 

I tuned a 69 Camaro with a GM ZZ383 that ran 11.80s at Atco.
Auto. 425HP version.
In first on street tires it spun them for as long as you kept your foot in it. And most of the way thru 2nd.
336 gears.
If yours won't do that, gears aren't the problem. It needs a distrib / carb tune.
But 336 or 355 work well for that torquey motor.

 

You cant get out of your own way w/3.08's

 

differential

 

yup. That's what we're talking about.

 

Not just in this thread, but in a brand new thread.

https://www.corvetteforum.com/forums...ferential.html

I wonder if, once again, we've been talking to an AI.

 

My 383 runs good has 600 eddlebrock carb light cam, electric distributor,40 over eagle rotating assembly eddlebrock 2.0 heads The vet burns the tires posie. What I am looking for is to burn the tires through 1st & 2nd all kinds of smoke, right now I get good 1st gear, churp 2nd. But maybe your right I need to advance timing. I used a Hayward 12" clutch so I feel drive line lockes up good no slippage, l probably should just settle but it's a fun car and am retired...... Thanks for taking interest in my vet look at pictures 😀

 

Uh, what is an electric distributor?

You want to burn off your tires through 2nd? You don't need a new diff (that would do it) what you need is something beside that POS Edelbrock carb. 600cfm on a 383 is just wrong. A properly setup 750 Holley is what you need.

 

Pictures?

lets stick with one thread.