Ideas.
We also have a 33.5 (1988) with the PYI flex coupling. We have purchased a Campbell sailer fixed 3 blade instead (see west by north enterprises website) as it is about the same drag as the old 2 blade fixed with increased forward and reverse thrust as well as what has been described as dramatic decrease in vibration. Only prop made specifically for sailboats and around $400.00 US. As far as folding, some dont fold back but the blades rotate instead, so that the leading edge points directly forward to reduce drag. Maxprop does this. You might want to also check Autostream and Martec for this feature. That way,prop and rudder clearance is not an issue.Good luck. Once we install our Campbell Sailer fixed 3 blade I will post a review for you other cost conscience sailors out thereHappy sailing