THE P-51 was built for speed. If I were you I would get a 2 blade APC with a low diameter high pitch and a spinner to match from Tru-Turn. The 2 blades are the most efficient.

My P-51 YS110 powered currently turns an APC 14/12 at 9300.

I may try the "warbird" propeller. The APC 13/13N. What do you think Richard?