Well, this is my first visit to the diesel forum. Never had a reason till now to look at anything deisel related. Anyway, I've now got a '02 2500 HD 4x4 with Duramax and Allison. Deal was just too good to pass up. Only thing I've done so far is step up to 33 ATs (yes, no lift, small mods to front inner liners) and I love this thing. It is truly a beast, but now I officially own a vehicle that I have no prayer of working on. /forums/images/icons/frown.gif Now my question, where is the best source of info on these things? I know about http://www.thedieselpage.com/, but I figure there are others. Main things I'm interested are: 1) Small tweaks to help performance (although 300/520 is nothing to sneeze at). I'm thinking 4"+ exhaust and breather upgrade plus maybe a VA box? When I can afford it that is. /forums/images/icons/laugh.gif 2) Auxilary fuel tank! What nitwit decided to put a 27 gal fuel tank on this thing? My Ram with 360 had a better range! Anyway, I want one to go under the chassis if possible. I'm thinking this thing will probably wind up with a camper shell on the back so filling a tank in the bed will be a pain. Although, a ~100 gal tank in the bed (top to bottom in the front) won't take up that much room, and I could probably mount a filler neck to the side of the shell... 3) Any other tips, tricks, warnings for a (mostly) diesel illiterate newbie?