Ok, ok..... forgive me if this is a repeat topic but i'm just curious. WhatÂ’s the correlation with Hp and mph. My boat does 68mph on the gps with a stock 454 and tight pump (12-jg with place diverter, droop and shoe/rideplate)....at 5200pm...( I can get it up to 5500 but don't want to sink the boat when parts start to shoot through the bottom end) The engine has a edelbrock intake, bassets, holley 750, and a cute little cam. Guy at the machine shop said to go with a different cam along with large oval BBC heads (049s are on the way) and a airgap intake with a 1" spacer. Said it should be a "sizable" difference in hp. Anybody think that hp will get me to 70 or am I just wasting time, $$$ and gas?????????????