Ferocity02

iTrader: (60)

Hello all. Later today I will be picking up an '01 T56 from a Z28, it will be going into my '01 Silverado extended cab. I would have preferred to get a GTO T56 due to the better gearing for trucks (especially in 1st and 6th), but they are hard to find, and the one I found is cheap! Is there a way to swap out the 1st gear gears to make a taller ratio like 2.97? What about 6th gear?

Thanks

85MikeTPI

iTrader: (9)

My SSR-hybrid PDF has a summary of T56 models with ratios and gear teeth in the Appendix A,C.

http://www.eecis.udel.edu/~davis/z28..._Fbody_T56.pdf

To change the ratio, you usually have to replace all the gears because of gear widths.

calhoon

iTrader: (6)

Converting 1st would require at least a clustergear and 1st speed driven gear swap. On a T56 most overdrives use a spool driven gear. This requires swapping 5th & 6th as a set. The best bet would be to use a GT500 gearset: It has a 2.97 1st but a 1.78 2nd... just the big step you are looking for. However, this is a TR6060 set and would require some trans building to pull this off in T56 castings. There are other posts here illustrating this.
Another added benefit is that 5th & 6th gearing can be changed independently.