Here is the update. My Rage now goes 75 with two and 3/4 fuel at 1500 feet evevation. I did the Tyler Crockett 454 kit that includes :

Adjustable Fuel Pressure Regulator
Custom Hydraulic Roller Camshaft
One Piece Pushrods
Rocker Studs
Roller Rocker Arms
Hex-a-just Timing Chain Set
2.250 Severe Duty Intake Valves
1.890 Inconel Exhaust Valves
Valve Springs, Retainers, Locks & Seals
Minor Head rework to increase compression etc.

The boat runs great now.

Congrats. That is great. Where are you from?

Old Scandia CB mid-60's @ 4500ft (454). All things equal, the Rage's stepped hull is faster. Buddy has Rage OB w/ 496 bout the same mid-60's @ 4500ft. Mine is mid 80s @ same elevation, but that comparison is apples & watermelons.