Oct 27, 2009 · Hey all, I'm new to this forum and looking for some help. I recently swapped out my 5.3L for a 6.0L in my 2003 silverado 1500. I basically did a straight engine swap, keeping the 4L60 trans and transfer case. I have a friend who used HP Tuner to flash the 5.3 computer to a 6.0 and tune it all up (the thing runs like a animal now!).