my lil bro has a 2000 gmc w/ 4.8 its pretty much stock, flow masterw/cutout msd 8.5 wires tbspacer k&n drop in filter and he uses my hypertech runs runs 15.3 in the 1/4 mile we ordered pacesetter lt's aem intake cutting the cats also is going to tune it nelson 93 when we can schedule to take it he's exited how much ya think itll gain sorryso long