I helped a kid put ARP's in his 05 last year, it had 275k miles on it, all 8 injectors were original, original oil cooler and the egr cooler had just finally ruptured, he had been on Edge tuning most of it's life, and on nothing smaller than a 37" tire since almost new. It was currently on 40" tires. He did an EGR delete and then finally started pushing coolant out. Did studs/gaskets at something like 285k miles. Last I had talked to him he was at like 315k, but I haven't heard from him in a while. That truck was a freak. He used to bust my balls all the time cause I was under 100k and basically replaced everything haha.
He had also bought a truck that had flood damage, it was used to haul campers around the US. He got it for parts basically but when it showed up to his house, it had 425k miles on the odo... no clue if it was original or not though. His personal truck was the highest I had heard of. I believe he finally replaced 1 or 2 injectors on his when we tore it down at 285k, due to stiction.