18ft. double eagle with a 302 v8 and 280 volvo leg (apparently has a 1.61:1 ratio, but can't confirm) how?

Question

motor over revs +/- 5400 RPM with an already aggressive 14 x 23 prop. trying to get the revs down. tried a bigger 15 x 21 prop but that felt terrible, hard to handle, speed felt slow. not sure what next to do if that is the ratio in the leg. thx in advance.

Answer 1

Turn the engine one revolution in gear and count the rev deg. on the prop or,

Mark the prop, turn the engine 1,6 revolution then check if the mark on the prop re-aligns

What rpm did you get with the 15x21