Does anybody know what size rearend was installed on '96 Z-28?? Or what the options were? What type of 1/4 improvement can I expect from from changing the gears on my basically stock car (just mufflers and KN)? What do you recommend for a car that will probably remain stock for, at least a few years? It has factory spec 245/50 Eagle GSC tires on 16 inch rims.

I've searched through the threads on this topic but couldn't find a clear answer. Help me out please. Thanks>!

 

Size, as far as gear ratio? Check your RPO codes (door jamb or glovebox). GU2 = 2.73. GU5 = 3.23. GU6 = 3.42.

Gear change (to 3.73 for auto or 4.10 for manual) makes a big difference in the way the car feels...much more pep in your step. A '93 formula that I installed 3.73s in lost a half second in the eighth...my '00 Z28 that I put 4.10s in lost three tenths in the 1/8th. Good bang for the buck.

 

ive always wondered if 4.10s were too steep...but now that you put it as "4.10 for manual" i realize its because with double overdrive M6s can get away with it. i love learning ****

 

If you have an automatic and can select first with the shifter, you have 3.23's. If it only lets you select second, you have 2.73's. Manual transmissions came with 3.42's.