Can you post the modifications of that engine and perhaps the dyno sheets? I am curious about something. 600 HP should be enough to push that boat at least 70 with the drive tucked all the way in. I'm not questioning your engine builder but I would like to see what components he is using to arrive at those numbers from an origional 415-HP engine.

Roby

This is the listing as far as the reciept of parts goes...
-rebuild 502 Mercruiser
-Bore and hone with torque plate 509ci
-port and polish heads and flow test
-balance crankshaft
-Magnaflux cranf and rods
-rubuild rods with boron bolts
-valve job
-surface and cc heads
-JE pistons
-JE rings
-Cloyes timing chain set
-Crane cam and lifters, hydraulic
-recurve ecu. Arizona Speed
-Fel-Pro marine gaskets
-Ferrea Inconel valves
-crane valve springs
-Vat and clean
-fit Clevitte performance bearings
-degree cam
-assemble
-Dyno 603hp @5600. soft rev limit @ 6200
Runs with fuel pressure @ 32-37psi
Timing @ 10 degrees advance at idle.
I know what you are saying....I should be able to get this up there even without going crazy trying to trim it up and pray for a little chop to air it out... The prop really has very little bite at all which is a big part of the problem. This stuff drives me crazy because it doesn't make much sense. I'm getting closer though....

I just switched to my Ballistic prop this weekend. I also picked up a bad batch of fuel with some water in it..... Always something. I ran most of the tank out. 3 water seperators later. Last night the bay laid down a little and I got it back out there. Still not pulling all the way through but I got some basics started. Weekends have too much traffic for real testing but it picked up a lot just in cruising...3-5 mph at 3500 and 4000rpm.