Well I just found out that the grinding noise coming from my back is infact my rear end going. My car is a 89 305TPI auto with I beleive its rear end is a 2.73 and there's a 91 GTA 350TPI auto with a I belive a 3.23 rear end. You think this would be a good swap for me. I"m pretty sure it will fit and the car was hit from the front so the rearend should be in good shape. What u guys think

 

Pull the cover and check the gears for wear and damage. If they look good go for it. I think you'll like the 3.23's. You can get an SLP takeoff posi for 99 bucks too and it will fit those 3.23's because they are 3 series, and the 91 has the 28 spline axles required. If it has a posi already you're ahead of the game. Snag that rear. While you are at it, grab the speedo gears too from the GTA. Check the swaybar too and see if it is bigger.

 

Well that sounds good to me, but does my 89 Formula 305TPI already have Posi or not. I'll see what I can do about getting that rear end, what gains do you think I would see from the rear end.