Cookee,
Mike Bontoft has these, 2X 1R 1L long hub 16/29
2x 1R 1L long hub 18/26
He's cleaning house! Do you have his contact info?
I have the same drive as you and have found that bigger diameter is better. I'm running a 17.75"x24" pitch four blade. Started with a three blade round ear 15"x20 pitch
Jeff