ok I have a 88 regal valanti xl 220, the 350 engine was locked, so im putting a 468 carburated bbc on it making around 550hp with eddie marine headers on it, I been reading about drives , pitch angles 3-4-5 blades and i'm completely lost, I want this boat to be a cruiser with some nice top end , I been a drag racer all my life, kind of new on boats, but this 2.0, 1.5 gears is driving me loco, also I want to this instalation to be as simple as posible while been durable as possible, thanks, possitive thoughs please!!!

If that motor is really making that much power it has to be doing it at a lot of revs. You would need to use a bravo1 but those dont like goin over 6k rpm amd i am sure your motor wont like doong it for very long either. Most marine 454 etc make 400 to 500hp tops at around 4400 to 5000rpm. A 1.5 ratio with a 4 blade bravo 1 prop will give you best all around performance. I m going to guess a 24p prop is a good start.

Poker has some good points. At which rpm do you make max power? If you spin about 5500-5700 rpms or more, the Revolution4 in a 25" would be a better starting point for baseline testing imo than the B1. Your hull would like the bowlift of the stock Rev4 more than the flatter lift of the stock B1.

You are right I keep forgetting how bad azz the rev 4 's are. I used one on my old boat and it was amazing.

my motor made 556hp @5700 rpm and 585 ft @4700rpm,thanks guys, what u think may top speed will be?

Well whats more important is where does the hp stop making anymore power. That's the rpm you want to prop to. No point dragging the revs out past that. Thats very goos power from that size engine. What exhaust are you using? There is no real way to saying how fast until you get a baseline. Also remember that after 70 in a boat that small you will need hydro steering or it will be scary and dangerous.

You will need to strap a set of 34" Maximus props to that horse. It will go really fast.

I think you got the wrong forum dude. Please keep this stuff out of other folks threads

For maximum speed, the Mirage+ in a 25" will also be a good choice. Speed wise you should shoot for high 70's. My guess is your x-dim is rather conservative around 14"-14½" so the Revolution 4 will work if you go for good mid range cruise and the Mirage+ will be the prop for speed.

but still it is going to have to be bravo 1 with 1.5 to 1 ratio in this guys opinion alpha that was probably on it stock will not hold up and also better think about upgraded way to mount the engine that much horse power is going to be violent at 5700 rpm going to need more than lag bolts holding it in

You want to run a B1 X or XR with 1.5 ratio. Replace parts when they fail. The cut out for the Alpha and Brave are the same, easy swap. Just remember to install a RWP on the motor if it ran an Alpha.