I need help and advice swaping my current 4.8 to a 6.0. Will I need a new trans? Will the same Trans fit on the 6.0? Wireing harness? What all would I need to re-place? Thanks a lot for your help and Advice   Brian  

Brian, it should be a relatively straightforward swap. As far as I know, both engines use the 4L60E tranny. Some of the 6.0s use the 4L80E. External dimensions and bellhousing pattern should be the same. I'll try to get the Truckin' tech editor to get on here and give you some tips. He might know.