I have a posi carrier from my 94 Firebird Formula parts car that a friend with an 89 Trans Am would like to buy from me. My problem is that I am not sure if its a direct fit? They are both 2.73 gears with A4's if that helps. I haven't dealt much with these years of F body's and am still learning. Thanks


ps...if it would work how much to charge for such an item?

 

if both are 2.73, then both are series 2 carriers, so , it should work, he needs to see if his axles are 26 or 28 spline(89 was the change over year, it could have either), the 94 is 28 spline, if the splines are the same, it will work, he would need to put his ring gear on it, reset the backlash, and there you go


if his axles are 26 spline, he can get some 90-92 28 spline third gen axles from a junk yard, its a direct swap


I paid $100 for my take out posi from SLP

 

I think 87 was the changeover year. So, IMO, it should work.

 

'87 was the engine change (2-piece to 1-piece RMS as well as centerbolt heads.) '89 was the change from 26 to 28 spline axles, and this added strength is what allowed GM to drop the 9-bolt rear from inventory.

 

Would it be the typical mid year build change? If thats the case then I could probably find that out no problem but I know if it falls too close to the date then we will need to check inside for sure.

Thanks for the help

 

You should check to make sure. I've dealt with a few 89 RS's and every one of them had 26 spline axles.