I have a 03 GMC 2500 it has 187,000 plus miles the 5.3 motor is the best I've had. In 187,000 miles I've done next to nothing to it I put tires on at 100,000 miles and a altanator at 150,000 miles and replaced the door hinges on the side cargo doors at 175,000 miles. thats good enough for me to...