ok my car has the 2.73 gears and i wanna do a swap...and u guys said i should do it to 3.42 and i was wondering if my speedo is gonna be off? and am i gonna notice a signifigant difference in how much more acceleration i have??

 

Yes, your speedo and transmission shift points will be off and need to be reprogrammed, and yes you will have more accelleration and less traction, too, probably.

If you have the Hypertech, I think you can change the speedo for the gear and shift points.

 

I made this swap on my 95 TA with a rear from a 99. Made a huge difference in acceleration but I lost two MPG's. Well worth it though.