I bought it for my 90 Silverado 5.7 1500... Without resetting my ECM I noticed a tiny difference in power but a big difference in mpg. Resetting the ECM game me a cool power difference. She accels better now and i can imagine I got more muscle to pull. My mpg is even worse now but MORE AIR=MORE GAS=MORE POWER... I was gonna buy the k&n but it's too expensive but I might look for a k&n filter if it ain't too much an it fits the mod.