ORIGINAL: JoeAirPort
I think you will get around 6900 with DA pitts muffler. I just read a thread about that prop somewhere. It's a good prop for the engine IMO (broken in engine).
I have 2 50's one has over 20 gallons thru it..I have a NX 23-8 on there now and it pulls like a train..I tached it at 6900 but still need to lean it a bit more..