Hello all, my '07 Avalanche has 215K miles on it. It has the 5.3L and I locked out the AFM with a device I plug into the OBD reader spot. It blows white smoke on start up, has an oil pan leak, a rear main seal leak, and one bad hydraulic motor mount. Since I will have to remove the engine anyway to fix the leaks I thought I would put a newer and more reliable engine and transmission in it. From what I've read, the 6.0L is the easiest swap. What model engine would any of you suggest and what transmission would be best for towing? The body and interior are top notch and I don't want to pay $50k+ for a newer truck. Any suggestions would be appreciated.