I have a 1994 3.4 5-speed. It has factory 3.23 gears in the rear end. I'm wanting to get a rear end out of a LS1 6-Speed. The rear end I'm looking at has 3.42 gears and limited slip. I was told, however, that if I change my gear ratio, I will have to have that tuned into my computer for my car to run right. Is this true? Or will I be able to swap rear ends and call it good?

 

Your car will run fine, but your speedometer will show a higher speed than actual. If you want the spedometer to indicate the actual speed, the computer will have to be tuned.

 

Can someone back him up on this?