I can't really help you on the exhaust, but I can help you on the gears. I just went to 5.29's from 4.10's with 33's, and I must say, it made a big difference. I personally would not waste the money on 4.56's though. You probobly already have 4.56's if you have factory 31's.


Josh
01 Chevy 2500HD: 6.0L gas 4x4 crew cab
in search of the next trail rig