The 25 & 30 horse motors (1951 through 1956) used a 10-3/8" diameter by 12-½" pitch propeller. The 35 horse motors (1957 – 1959) used a 10-⅜" by 13-¼" prop. You might got away with the higher pitch on a small hydroplane, but not on fiberglass runabout. The 30 horse thrives on high RPM. The higher pitch would not let it turn up to it’s full horse power.
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