Chevy 2500hd w/ 6.0 gas, exteded cab 4x4. I think that is going to be my next truck. Anyone out there who has one, are you happy with it and what kind of gas milege do you get? Diesel would be nice, but the actual diesel is more then gas, and the up-front cost of the truck is alot more. But I would like that allison tranny. Thanks.