if you're gonna suck the gas with an 8.1 stick with the truck.. Trucks with 8.1s came backed by the allison trans.. burbans kept the 4L80E
as Scotty stated a 1500 with a 5.3 and a set of bags will more than do the job.. if you wana pull a GN down the rd or step to a fullsize rig id lean towards an HD with the 6.0 and get the PCM tuned !! these trucks in stock tune are DOGS !!