Let's see... H9 P-51... Webra 120 (mounted inverted as idle is not really an issue)... Jett Engineering "Jett Stream" exhaust (down the side of the fuse)... 13x13 prop (we need 13,000 RPM on a 13 inch pitch prop, adjust nitro to achieve it)... Very tight linkages, with no slop or flex. Full bore... 10 degree down line. In theory 150 to 160 mph??? Oh yes, you might want a box to carry the pieces home in. I can't imagine it won't flutter. Good luck, and let us know how fast you can get it.