Rjaimw

I have a 04 burb w/ a 8.1 I get 8.5mpg in town . There arent many choices as far as mods but I like the 496. I had a 03 silverado 2500 w/ a 6.0 that got about 9mpg. If I could afford it I would put a duramax im my burb but since I dnt Im glad i have the 8.1. Ive hooked up to a 6.0 and pulled it sideways

Kerr

I've got both as well. To modify get the 60 however both of mine are pre 08s so they have 4l8e. The 08 will have the 6 speed which will help out a lot. My cammed and supercharged 8.1 runs as good as the wifes 2011 denali granted there 3k lbs lighter