I have a black 2004 rcsb swapped from 4.8 to 6.0 and it has less than 50k on it. installed eaton lsd in the rear and has a do it to the max wheatley tune. fully built 4l60e tranny. 3-4 drop. Interior is gutted and/or painted because I was testin things out. I know it will run low 13's havent ran it since lsd install. 20's with low profiles also. I need to get about 13 for it.