Sharkey - If you are running a one-piece Mac muffler, I'd suggest the 11.5x4 APC. If you are running the Mac tuned pipe with the seperate header tuned properly, you can try the 12.25x3.75 APC. In the wood variety, I'd suggest the 12X4 in the B Y&O from Brodak at http://www.brodak.com, or a 12X4 in a Rev-UP (if you can find it). The 12X4 Zinger is all right, though does not offer the pulling power of the others that I have mentioned above even with the modifications, though does increase its performance.

3Dreaming - I did check Brodak's website, and they do not have any Rev-Ups listed. I presume Tom that they sent me a catalog because I was asking about becoming a dealer for their props. Sorry that you did not receive a catalog as well. I am going to contact them about the Rev-Ups. I will let you know how I make out.
Kevin