I have been looking at diesel trucks and may end up in a GMC. Wondering about mods. I have heard that it is more difficult to add mods, cold air intake, exhaust and chips, to the Duramax as compared to the Cummins. Is this true?

What mods would you recoemned for better mileage?

get some coffee.. do some reading..check out the Power and Performance sections..should have all you need to know. Good Luck with the upgrades