What prop should I be running??
 

This boat is new to me and I started to see what kind of speeds I can get out of it after owning it now for a couple months. Its a 288 Sunsation Intimadator that has a 377 stroker with a Bravo 1 drive and 22P four blade Bravo 1 prop. This is whats happening as I went for top speed...The RPM's keep climbing past 5500 and would likely pass 6000 rpm"s but I backed off as soon as it was still climbing at 5500. The boat planes out amazingly fast with Zero effort and the gas mileage seems pretty darn good aswell!! I usually run 35 MPH at about 3500-3600 rpm. This boat must have the wrong prop!! Or is the Tach out of wack?? I believe Max RPM on this motor should be 5200 rpm's

Tach is off assuming the motor ECM hasn't been altered.

What is the out drive ratio?

1.65

What top speeds are you seeing? Most likely could go to a 24 or possibly 26.

I dunno. Thus is a 28 foot boat with a small block in it.