I'm running a fresh Gen VI 454/330 complete roller motor, Holley 650, Mallory Unilite optical distributor, 4" Stainless Marine exhaust and a labbed Rev 4 22P prop. The motor should be turning 4600-4800 RPMs. The best I have been able to turn is 4200 @ 46 mph. I'm still 400-600 rpm short of where I should be. Any help would be greatly appreciated. Would a high rise manifold & a bigger carb make a difference? Maybe a different distributor? I'm at a loss at this point.

I would think the carb would be the limiting factor.

I'm thinking carb as well. I would run a 600-650 carb on a 350 sbc to spin around 5k. I think your 454 needs more fuel, generally when you run out of fuel, it feels like your motor hits a wall and no matter what, just won't move any quicker, almost like there is a throttle stop. If you are hitting 4200 and stopping dead, I'm going to bet that is why. Find a take off marinized holley 750 and just drop it on. See if you can find even 200-300rpm's. If you do, then it's time to mess with jetting and intakes to get the combo just right. I assume you did all this, but fuel lines aren't collapsed and filters are new yeah?

I'm looking for a Holley 750 cfm now. Yes the filters & all fuel lines are new and not clogged or collapsing. I feel like a dog chasing its tail...

Check your PM.

Replied to PM check your box...

Showtime Facelift Phase II...
 

Wow found the first phase thread. Maybe I'll just continue phase two in this thread...

Getting ready to put SHOWTIME in the upholstery shop this month. I still haven't settled on a color scheme yet...

I finally got SHOWTIME in the upholstery shop today. They said she should be ready for the water by mid April, Went with white, red and black color scheme that should start with the engine cover and work its way into the cuddy. Keep your fingers crossed for me that it turns out nice. I took it to a shop 60 miles from my house so I won't see the daily progress on it.

instigator did you figure out your rpm problem. I had the same problem with my Carrera it has a bbc and when I had my holley 750 on it I got 5000 with a 21p rev 4 then I put a quickfuel 850 on it and got 5400 which was too much, so I put a 25p on and getting 5000, so you might want to test out another carb.