My catto prop set up called for longer drive lugs on the crank flange to accomodate the fixed pitched prop which has couter bore to accep these longer lugs. There was no way that these could be installed because of the lack of clearance between the engine casting and the rear of the flange. So, I called Catto, who contacted their machine work vendor, Saber, which in turn sent me an adapter that moves the prop out about 3/4 of an inch. No big deal right now because I was just setting up my cowl. Good thing I caught it. Saber sent up the adapter and new prop bolts (for a cost) and I assembled it all. Did a mock up of the prop in relation to the cowl to ensure I had clearance.
