What sort of power gain would just I/H/E have on a stock engine?

 

that all depends on what kind of intake, shorty or raceheader, and exhuast.

 

with CAI, RACE header, exhaust + tuning people have gotten upwards of 200whp. from a baseline avg of about 165-170whp. for the K20A2

there is one person i know of that has 190whp on CAI,RH no tuning on a K20Z1.