Hey guys, I'm in the middle of a rear end swap (Standard 8" rear to a stock firebird posi unit) primarily for the disc brake set up and the posi on the new one. My problem is that the original rear end has different gears in it (not actually sure what they are... its from a V6 car) What I want to know is if I can take the gears from the old unit and install them in the new one.. and if they still work with the posi . Any info would be a great help.. Thanks

 

Never heard of a 8" rear in these cars. Or any GM for that matter. So right there, there's no way we can tell you, until we know what model(s) of rears you're working with.

Once you establish that both rears are at least the same model, then whether the gears will work, will depend on the ratios.

If both rears are 3.23 & up (3 series), or both rears are 3.08 & down (2 series), then they'll swap over; if you know how to do gear setup. If one is 3 series and the other is 2 series, then no they won't. Although, if it turns out you want to put 3 series gears onto a 2 series carrier, you can buy a spacer to do that. However there's NO WAY to put 2 series gears on a 3 series carrier, unless you know where to buy a spacer that TAKES SPACE OUT instead of PUTTING SPACE IN.

 

Yeah sorry I forgot which rear I have... I really need to check on that.. but thanks for the info I'm sure it wil help