Trying to decide which rear to go with 3.73 or 4.10? I have a M5 transmission for my 89 TA GTA.

I was told with the A4 Transmission that 3.73 is all you need otherwise you wouldn't be able to hook up the well because 1st gear in these transmissions are aggressive. I don't know how my transmission technically is so which gear would be better for me?

 

What's your engine's peak torque and peak HP RPMs?

 

With a 26" tall tire and street/highway use, 4.10 gears are only fun for stoplight to stoplight driving. You'll be much happier with 3.73 or something in the mid 3 range.

There's nothing saying you can't run 4.10 gears but your engine rpm will be well over 3000 rpm while cruising down the highway. Those high rpms mean really poor fuel mileage.

 

I think I am going to go with the 3.73's. I also plan on putting new heads and intake on so I think I will be satisfied with the 3.73's