Thanks a bunch for that J-bird link. That's just a 5-hour drive from me, so I could run over there with my engine for a fitting.
I'll check out Arrow Prop, too. I have a link saved for an outfit in California, that would even calculate the drive ratios for you, once they had your engine info and prop intentions. Low cost hub assemblies, and modular, ground-adjustable pitch props.

I've also thought about a VW engine and direct drive, but VW stuff is getting a bit expensive anymore. It wouldn't be too terribly hard to build a 1/2 VW, or use the whole four cylinders. I'm just a bit concerned about all that weight being that high in the hull.

We'll see where things go.

Roger