My daughter has a 1982 tall rig Catalina 30 with the venerable 5411 diesel. It has a two blade Gori 13" x 9" folding prop. After repairing, cleaning ( the 1 5/8" ID riser was down to 1/4") and reinstalling the heat riser the engine does not overheat and it revs up to 2976 rpm at WOT. Rated rpm is 3000. It will do 5.4 kts now at WOT. The boat has a spare two blade fixed Michigan sailor prop 12" x 12". Does anybody have any experience with that prop. I'm sure reverse would be better just wondering about forward performance. There are strong currents here in the PNW...I know a three blade would give me better punch but since this is a spare already on the boat the cost is zero. Thanks, Mike