Got a 02 2500HD extended cab. Have UPD,HPP3 and a Flowmaster catback system and Taylor wires. I wonder if the ASM headers would help milage when I am not standing on it or make no diff?

Anything you guys have found to help other than taking the 200lbs of sand bags out of the back, traction, that I can do? I have 34inch tires and a billet and HID lights up front but thats it for looks.

Thanks again guys,

Jon

 

anything that you do to improve airflow into or out of the engine will increase your gas mileage, id say it will be a noticeable difference because of how much better they flow than stock manifolds. i noticed a difference with the gibsons that i have, and i know that the ASMs are a lot better