Big Matt

I just have a quick question.

I grabbed a posi unit out of a car that had 3.42 gears on it and want to put it in my car that has 3.73 gears on it. Will this work? I was told by someone that it wouldn't but I'm not sure.

Thanks for any help.

jmd

iTrader: (4)

It has to be a 7.5" or 7.625" GM 10-bolt. These go from the late 1970s through past 2002 or later. There's also a couple larger GM 10-bolt axles like the 8.2", the 8.5" and it's nearly compatible successor, the 8.6", none of which fit your third-gen rear axle.

Your axles have to match spline count. 26 spline was used from the 70s through the early 90s. 28 spline was used 1989 and later. The 89-92 stuff is tough to tell if it's 28 without opening up the axle.

Carriers are either intended for 3.23 and higher and called "3 series" carriers or 3.08 and lower and called "2 series" carriers. (There are also aftermarket thicker 3 series ratio gears that fit 2 series carriers and spacers that allow 3 series gears on 2 series carriers. Try to avoid the spacers.)

So you have three things to check in order to determine compatibility with your car's rear axle.

Big Matt

Thank you. Everything matches. I was told that they had to be the exact same gear ratio, but that's not true. I guess who I was talking to didn't know what they were talking about. thanks again

jmd

iTrader: (4)

You're welcome.