I OWNED an 04 F250 6.0 Powerstroke. 4" exhaust, cat delete, cold air kit, Diablo tuner. I know what they run like. Besides all that, I've turned wrenches since 1974, so I've been around some diesels. I stand by what I said. Even with all that done to mine, a good hot gas engine would out rev the hell out of it. I didn't say out run.