ok why a 6.5??? take it from some one who works with those motors day to day(USMC Motor transport mechanic) and i wouldn't use one of those motors if it was given to me! if your gunna do a diesel and are goin to go with a mechanical go with a cummins. my DD is a 2002 Chevy 2500HD with the Duramax and it is a great motor but they are a little exspensive to get ahold of. but anyways i like your axel decision. just think about a different diesel motor