Here's my 98 Sierra 1500 single cab, short bed, 4.3L Vortec, 4L60E. All I've done to it so far is remove the baffle off the throttle blade, descreen the MAF, add a $65 cold air intake that works awesome. Added some platinum plugs. I also put a resistor on the IAT sensor. Got 40 series muffler, single in and dual out with magnaflow tips. She still sounds like a V6 but with a little more balls. I'm growing a fond respect for these V6's now. Any questions, just shoot. Enjoy.