I'm running a '74 Chrysler 135 (1.78 gear ratio) on my '77 Glastron 188SSV. Top speed is about 34 Mph at 5000 rpm, prop is 16" pitch. I could easily rev the motor to 6000+rpm. FSM tells me that the motor should have come with a 19" pitch prop, so someone probably changed it.
Seeing that...
