Rear axle ratio

[minifridge1138]

Correct me if i'm wrong, but isn't the rear axle ratio 2.72:1 in the 1982 Corvette?

That seems low to me. It is great for cruising and gas mileage, but wouldn't 3.7 or 4.1 provide much more low end torque?

My corvette is no longer my daily driver, so i'm more concerned with smiles/gallon that miles/gallon.

Is changing the gear a common thing?
Where could I find a new gear?

Thanks!

 

[TJay]

You are correct, 1982 was 2.72:1 except with aluminum wheels which was 2.87:1. A nice all around gear might be a 3.55.1, better off the line pull and still good fuel mileage.

 

[minifridge1138]

Ok, thanks for the advice.
Is this the sort of thing that a local parts store would have, or would I need to find a salvage yard?

And this is a newb question, but what do I say i'm looking for? The ring and pinion from the rear axle, correct?

Thanks!

 

[Vettehead Mikey]

It's unlikely that a NAPA type store would have them in stock, and I would personally NEVER re-use a ring and pinion from somebody else's diff.

You may want to consider buying a complete unit for your car from a rebuilder, or sending your unit out to a competent vendor and have him convert it.

This is not a job you can do with simple hand tools underneath the car.

 

[minifridge1138]

I've worked on rear differentials before. Replacing bearings and lubricant. But i've always put the original gears back in.

I just hate taking my car to the shop. I haven't found one that i trust.

Thanks for the tip!

 

[Glensgages]

Correct me if i'm wrong, but isn't the rear axle ratio 2.72:1 in the 1982 Corvette?

That seems low to me. It is great for cruising and gas mileage, but wouldn't 3.7 or 4.1 provide much more low end torque?

My corvette is no longer my daily driver, so i'm more concerned with smiles/gallon that miles/gallon.

Is changing the gear a common thing?
Where could I find a new gear?

Thanks!

3.73s or 4.11s would give you much-better torque out-of the hole, especially if you still have the Cross-Fire, but combined with the 3.06:1 ratio of First Gear in the 700-R4, 1st Gear is awful -short:
I had the swap to 3.73s done, and it woke-up what little performance the Cross-Fire could offer.

Go to either JEGS or Summit, and search 'Dana 44 ring & pinion', but make-sure you get the proper set for the Series 3 carrier (or is it a Series-2 carrier, because they originally came with 2.72/2.87 gears? ):
I'm almost positive that Series-4 equipment won't work in an other-wise OEM rear-end.

 

[minifridge1138]

I don't have the crossfire, but i have the same cam, heads, and transmission.
When the engine is nice and warmed up i can get a tad of squeal at the redlight, but my power is gone as soon as i get into 2nd.

Thanks for the advice. Now that i know what to look for, I can learn more.

 

[Glensgages]

I don't have the crossfire, but i have the same cam, heads, and transmission.
When the engine is nice and warmed up i can get a tad of squeal at the redlight, but my power is gone as soon as i get into 2nd.

Thanks for the advice. Now that i know what to look for, I can learn more.

That is as-much because of the wide gear-spacing in the 700R4 as-much-as anything-else:
you don't make much-power to begin-with, and the drop from 3.06:1 to 1.57:1 in 2nd Gear lowers the RPM below the power-curve, but 3.73s/4.11s will help this some.

 

[howard]

another option...
http://www.tomsdifferentials.com/index.asp