Speaking of high RPMs: I'll never forget the first time I brought the MJ back to Hesco for my first dyno run about a year after I had installed their crate engine and done some exhaust and intake mods. The man himself, Lee Hurley did the test, while I watched. He made several short runs up to 5000 ear-splitting screaming RPMs while I cringed, held my breath, and waited for the engine to explode. It didn't, and when he handed me the the new printouts, it was a pretty good increase in torque/HP over the originals.
Since then I've had 3-4 more dyno runs all done by Lee (he likes MJs :D) after other mods I've done to confirm the improvements, and I'm not nervous anymore. These engines can spool up pretty well for short bursts, as all the ricers in my town now realize, although I don't do it often since I've snapped and axle w. the freaking D35. It's fun though..