Does anyone know a good formula for calculating a good prop pitch? I have a 1997 23 ft Caravelle Interceptor with a stock 454 300 hp which I added headers and a fast EZ fuel injection system. 10 gal/hr at 40 mph. I either run a Ballistic or Mirage 23 pitch for water skiing and general use. Speed is 63 mph at 4800 rpm which is right at the rev limiter. I run a 25 pitch for long range cruising which gives me the same speed but at 4500 rpm. Here's the catch, I recently purchased a 415 hp 502 Mag and bought a 27 pitch mirage for the extra hp. However, before installing it, I took it to a marine racing shop and went crazy with it. After stroking it to a 540 then .30 over boring and 9.5 compression pistons, and $13,000 later, The dyno showed 576 hp at 5200 rpm and 637 lbs ft of torque. That's my Delema. I don't want to buy any more $600 props to test it. I am thinking a 31 pitch at least. Anybody know a formula? Anyone have similar hp in a 23 ft 3500 lb boat? I may even need a 4 blade with all that torque. Mike

I’m thinking the 27 might be pretty close, you’re going to want to run it in the 5200 range, not down in the 45-4800 rpm range like you did with the old power