I ran an APC 11x7 on my .455 without the baffle and flywheel weight. It would pull the XE2 off the ground in about 6' and go almost vertical. The XE2 is a heavy trainer too. I have plans for some .40 sized planes and I'll put it on one with a Towers muffler. I gained 1000 RPM with my .46NT with one. Also, these engines really need a hotter plug than the OS 8. You will be surprised at the power increase with a Towers plug.

The .40 and .46 have the same pistons. The liner is thinner on the .46 to give a larger bore. The crankpin on the .46 crankshaft gives it a longer, but less balanced stroke.

Our hobby shop has the .40, NIB for $62.99.

I have about 3 or 4 of those 3 bladed props. Every one of them were severly out of balance on one blade. It took a massive amount of shaving with a Dremel to balance them.