67,000 miles on my chipped 7.3. Only problem I had was the connections on the chip got dirty/corroded. A little emery cloth and it was good as new. From what I read, my 7.3 with a chip is about the same as the 6.0 stock but the new motor is quiet. I dont think you can go wrong either way. I kinda of like my noisey motor and with the K&N filter, the turbo whine is great.