and are props in much higher pitches even available.......???

I have put 875hp through a Volvo SX drive with no problems. Had the boat for three years before selling it. New owner still loves it and he has had it about 4 years. No problems. The SX has the same upper as the DPX. The lowers are interchangable. I have seen guys swap out the DPX lower for a SX lower and pick up 5 mph. The volvo outdrives are stronger and better than the Merc stuff in my opinion, just harder to find aftermarket parts for.

Hope this helps,
Chris