Jim I reply you tomorrow because know I don't remember exactly the dimension you're asking for.

Dan I'll power the Supreme with the YS 140 Dingo. I fly with that engine since the first prototypes and I'm very happy with the way it perform; I found a real difference after Chip suggested me to switch from the Cool Power 20% pro pattern to the 30% heli type: awesome! It helped me a lot during the last unknown round at the EC finals in Spain in that umbelivable wind!
Good props are 15.5x12.5, 16x12, 16x10, depending on model and flight style. However the Supreme has been "thought" to accept and fly well also with 2 stroke.

'till next time......

Marco