Hello everyone, I am totally new to the Duramax scene. To be honest I am looking into this for my father. I have a Trans Am personally that I am working on, current mods are Weiand/Lingenfelter LS6 intake, catback exhaust, Hotchkis LCAs and adj. Panhard rod, Eibach Pro-kit, and a few other goodies(it would take a while). My father has a 2004 LLY 2500. Its a 4 door 4wheel drive. I love the truck and so far all he has done was wheels and tires, the 16" stargate chrome wheels. I had a couple issues i wanted to research so I figured yall might could help. I can tell ya all you want to know about LS1/LT1 motors but this LLY motor is a totally new frontier for me.