My brother has a 2004 Yukon XL, he's got about 260,000 on the clock and the motor blew (5.3) we are gonna replace the motor and trans. LS motors seem to be a dime a dozen used, so my question is what wiring/tuning issues would be run into if we went LS versus another 5.3 we are hopeibg to see another 100,000 out of the vehicle