I'm looking for a spare prop for my 1967 Johnson 20HP FD-21. The prop on it now is a Michigan PJ16. It works OK but it's a bit battered. I don't know if it's original (did Johnson motors come with Michigan props?). The OMC parts catalog lists 3 available props by part #:<br />381801 9" X 10 1/2"<br />379717 9" X 9"<br />592959 9" X 10"<br />Is there a site that indexes Michigan prop numbers with Johnson part numbers? I've seen a Michigan PJ19 and a Michigan "AMC 202 12 pitch" on ebay; both looked like they'd fit but who knows from a picture? The seller of the second one said it's for an 11/16" shaft - too big for my motor. Yet he swears it's off a 20HP shearpin Johnson. Did Johnson use two different diameter prop shafts on their shearpin 20HP models? Used props go pretty reasonable on ebay if you watch for them, but if they don't fit the motor they're just nifty paperweights.