I have a T-56 out of a GTO
1st: 2.97
2nd: 2.07
3rd: 1.43
4th: 1.0
5th: .84
6th: .63
tires: 255/40ZR17, 25" diameter
wheels: 17X9
LS3 w/430hp, 424 lb. ft. storque
I am happy with the 3.42, but really have nothing to compare the car to as these cars are the most insane thing you will ever drive.
Traction, or the lack thereof, off the line really limits the potential of my car. 1st gear is unusable. 2nd gear works just fine 99% of the time, but it is super easy to break the tires loose under moderate acceleration. Tire spin in 3rd and up is not a problem.