Steve, I only reved yours a bit past 8000 on the dyno. We had it set at 8000 most of the runs, then I bumped it up to 8200, to keep from hitting it so often. Fix the fuel and lets turn the boost up to 35psi.
Running a 2.4l at 8500 is like running a 2.0l at 9600. The piston speeds are very high at those RPMs. Probably a decent amount past what most V8 engine building books would consider reasonable for even a race motor.
Getting a DSM to make good power past 8500 RPMs anyways takes a lot more parts and work than most have. Back on my 2.0l, I think my peak power was around 7500, while on the 2.4l, peak power is around 6600.