I am going to estimate 4600lbs with gear, fuel and people in it. It isn't packed full of stuff, it has a 60 gallon fuel tank and is usually 2 people in it. 4 at most. Keep in mind that the keel was taken out of the back of the hull, not sure if this is good or bad yet.

Because its a solid roller and will need valve lash checks every 25-50hrs. IMO, it also has too much duration. Solid rollers make there power at high rpms(6000rpms+).
For a marine engine, you want a cam that will make more torque at lower rpms.
You won't get 650hp out of a NA 502ci unless the engine is spinning 6000rpms.
You need to make sure the engine is tuned correctly before you try to prop it correctly. It could be that the timing is way off.

Your boat is listed at 4650lbs dry weight. With fuel, light normal gear, and 2 people, you will be around 5200-5300lbs min.

Thats going to be the first thing i do is check the timing. I'm also going to ask the builder why the timing is locked out. There is no advance on the timing at all. With no advance who knows how much power I'm losing.

26 inches of pitch at 5400 should give you 78mph with a 13% slip.

This is what the boat should do with 650HP. Give or take of course. 80mph would not be out of the question.
It usually goes back to HP.

Brett

Got an update. The prop i was running is a 23P that was re-worked and apparently one of the blades were a little bent so there was some slip there. I added parabolic rake and sharpened leading edges. I was running 5000RPM with this prop already so well see where this goes.

How did you add parabolic rake?

Brett

Talked to hydromotive and they recommended marks performance props in shelbyville indiana. He is doing the work today and shipping the prop back to me tomorrow. Should have it Thursday for a test run on Friday.

Most likely, it has locked timing to help it stay running at idle with the solid roller cam. Running locked is fine as long as it is set to 32-36* but it can be hard on the starter.

It does have some sort of high torque starter on it, reminds me of my old drag strip days ( the sound of the starter ) . Would it be possible i will see more top end power with having a mechanical advance? Right now, it runs perfectly fine at idle and i would be OK with it running a little rough i think it sounds better any way.

Can't change parabolic rake. That is built into the blades. Small rake angle adjustments can be made other ways though. Maybe that is what he was talking about.

Brett