I will say 70 with a 24p prop your torque numbers are low. My guess

I ran 60 with a 454mag with 550 hrs and a 22bravo. Boat gets water tested in a few weeks and I don't think 75 will be an issue

Thought I would report back...

1997 283 convincor (standard cabin). Bandit Performance Marine 600hp 460cu. Bravo1 drive.

The engine builder went out yesterday for prop testing. Hydromotive 25 didn't work well. Went to a Bravo 24 and was seeing 75mph consistently but was still shy of 6k redline and needed to really trim it out. IMO, labbed 24 is probably where we need to be but we will see through more testing. My initial thoughts of a larger prop proved to be wrong b/c this is a high revving motor. I can't wait to take a ride, hopefully tomorrow! Would like to post pics but I have no idea on how to do that

Sounds like fun!! When you post, go to Go Advanced. If you have rights, there will be a spot to manage attachments.. Lets you select a file on your computer to upload. Lets see that bad boy!!

i dont see any option for "manage attachments when Im in "advanced"

How is the new engine running? what did you decide for props wjat numbers are you seeing?

73-74 GPS with 2 people and half tank but im only turning 5300-5400. I need to turn 5800. I might lab the 24 bravo but I want to try a few more props this week. Mirage Plus 25 and Rev 4.

Have a buddy here on Barnegat bay with 283 has 800-850HP minus 3" shortie lower turning 5 blade 29P prop GPS 91+ MPH.
Slower to plane but better everywhere handling etc.

Update:

Best all around prop is Mercury Rev 4 21p. It carries the bow nice and high like a mirage but with no cavitation. Bravo 22 was very close to top end. I'm sure a mirage plus 23 would give me 1-2mph more but holeshot, mid range acceleration and cruise speed would be affected. Boat/Motor doesn't like a lot of pitch. Ive tried Bravo 22, 24, Mirage 25, Rev4 23 and 21. btw -my speedo is dead on against my GPS. Conditions werent ideal. 90+deg with high humidity, 2 adults 80gallons of fuel in fresh water. Excuse my commentary at the end....I've tested so many props over the last month i was getting frustrated

http://www.youtube.com/watch?v=ovd_G...ature=youtu.be