OS DF..
Yeah, I had a OS DF engine running the exact prop Dustflyer was running (I was turning just slightly higher RPM's at 3250' ) on a Dust..matter of fact I sent him that prop just to see how the Jett 50 would turn against it.
Unfortunately, My Whiplash won't balance with the OS, gotta go for a couple more HP...
And I still don't think they'll go 200 with a 9X7 or 9X8, just MHO.