Nice! At what rpm?

+1

Sold my props on the last two builds. Then, after they were tuned, I paid money to have BBlades lab me a set of new props that were the same or similar to what I sold.

If anything, its worth running the old props with new power for a baseline. Your prop guy might be able to put a little more pitch or tune and achieve more than starting with new props.

The boat has/had 24P Bravo 1 props prior to rebuild/additional power. I was thinking jumping to a 28P Bravo 1 would be the play. This seems to be what most people run at this power level (500HP+) and this hull (33 powerplay).

I ran 28p four blade on my 33 OL but I was around 620 hp...........if the 28's are to much you might try the 25p mirage +

I personally think youd have to gain a bunch of tq to spin 28s if you were previously spinning 24s. Try to borrow props before you buy any if possible, smitty

You can test drive props with BBlades

I agree with Articfriends, Not necessarily the HP, but you need some good torque curve and power to go from 24s to 28s. The best way is to either to truly dyno the motors to know what you have, or borrow some props. I would start with some 26s. Just my opinion. Good luck on getting them dialed in

The 509's were spun at 5700 on the SCARAB and 6000 on the Daytona with the 1.5 ratio drive.
I run labbed Bravo 28 four blades on my Daytona. But I am spinning them with a 1.36 ratio drive and 6100 RPM.
If it were my boat I would try the original props. You will want to spin the new engine faster anyways.
You create your HP in the heads on a BBC. If you just changed heads and didn't have them ported or bought them CNC'd then you will see an increase in HP but probably not as much as you think you are going to get.

Those engines had a LOT of tinkering done to them. So there was a lot more to them than the parts I listed.
Those engines and the 598 were put together with a LOT of expensive parts and machining.