[gtoformula]

Originally Posted by shineybike

I have an open rear in my Lemans. I have a complete posi rear with 2.56 gears. Can I swap the 2.56 gears in the posi for something in the 3.08 or 3.23 range? I've read many posts on this subject and was under the impression my 2.56 carrier could go up to 2.73 gears. I've also read that 2.56 is the high(numerically) end of my carrier. Can anyone clear this up for me once and for all? What's the deal with spacers? Also, if my open rear has 2.56 gears, will putting a posi with 2.56 in the car do much for me? Is it worth the cost? The car has the stock 350 with a 4 bbl setup, dual exhuast. Just a driver, but I'd like to get a little better acceleration from a stop while keeping it highway friendly. Thanks

My 1970 GTO had been converted to a peg leg 2.56. I put in an Auburn gear posi with 3.55 Richmond gears.
There are two different carriers. The info I found was that your carrier with the 2.56 gears will go up to 3.31. The next carrier goes from 3.36 to 4.56 gear sets.
A posi with 2.56 gears won't be of much value. The basic concept is to have two tires get traction rather than one. With a stock 350 and the 2.56 gears my guess is that you have one of two situations when you nail it from a standstill:
1) - the right rear tire grabs and the engine lugs until it gets some RPM.
2) - the right rear breaks loose and you have zero traction until the car gets rolling.
At least that's what would happen with my car when it had the 2.56 with a TH400 trans.
You can put in a posi carrier with 3.08's or 3.23's. The 3.08 set will be more highway friendly, but the 3.23 set isn't bad either. With the 3.55's I was turning about 3,000RPM at 70MPH. After putting in a 700R4 trans it now only turns about 2,100RPM at 70MPH with the 3.55's.
Spacers? What kind of spacers? To space the wheel out from the axle?

[shineybike]

I understand that with the 2.56 open rear I'll get one tire spinning. I was wondering whether replacing the open 2.56 rear with a posi 2.56 rear would give better acceleration from a stop. The other question was whether I could go to a numerically higher gear set with the 2.56 posi carrier? I've read where spacers are used to jump up to even higher gears, but I didn't know if you could go from 2 series gears to 3 series, as in going from 2.56 gears to 3.08 or 3.23. Thanks

[Grand73Am]

The spacers are used on the carrier when you want to keep your 2 series carrier and use a 3 series gear on it. Here's an article that may answer some questions: http://www.chevyhiperformance.com/techarticles/48518/