02 3500 GMC D/A 4" exg. Hypertech Wanting to upgrade air intake ,want to be clean air, but max air ? Also what type if any fuel add. needed and why ? Iput on a lot of pulling miles with RV Also advice where to buy ? One more what is a high idle ? is this a kit and what does it do ?Edited by: James R.

Best advice I have is to search the topics you mentioned. More info then you can read in one night on the air filter alone


Additive is the same thing.. agreat debate indeed..