Is my HypertechIII good for my truck??

[2 Amigos]

Hey guys, the truck that I just recently bought (97' C1500 Ext. Cab, 5.7L Vortec) has a 10'' lift, 4:56 gears and 35'' Toyo M/T tires. I was doing research and the manual only adjusts to 34'' Tires and 4:10 gears. Will getting another tune, or possibly a custom tune, really help my performance? And if so, by how much? Thanks

-Tony

[VinceTrifecta]

I usually see anywhere from 15 to 30 RWHP when doing a custom GM tune, depending on the vehicle, its mods, and how close the original tune was.