Geez........ it's been a while, but no one else has answered, so.........
IIRC, 17 1/4 and about 10,600 with an Eather 3-3/4 pitch 3 blade prop, *about* 12" diameter. That was with Randy's "old" 40-46 pipe.
I could be off here, but maybe it will spur someone to correct me!
Bill <><