I purchased a Catto 3-blade propeller. I had the prop sized to achieve engine redline (2700 RPM) at 8,000 feet. My engine and prop combination is estimated to yield 210 MPH at 75% cruise power and about 227 MPH wide open.
Here are the specs: 3 blades, 66-inch diameter, 78-inch pitch, SAE-2 bolt pattern, 1/2-inch bolts, 3/4-inch lugs on a 7-inch flange.
I had Craig paint the prop solid black. I did this to purposely disguise the black exhaust soot that gets deposited onto the blades while flying. With a 4-cylinder engine, it is impossible to clock the prop to eliminate soot deposits. You either clock the prop so that one blade gets alot of soot, or you clock it so two blades get some of the soot.
I bought an 8-inch prop extension from Saber Manufacturing. Wow, what workmanship! I swear it's a piece of art! If you need a prop extension, Saber is it. Here's a picture of the prop extension being fitchecked on the engine.