Just dropped in a 900hp (on dyno) motor. Imco drive -2 lower. 28pitch b1 4blade. Drive is 1:50 ratio. I had it out and best I could get on GPS was 76. Kind of funny but with my old 496 carb motor would only go 76 on the same GPS. So I'm guessing GPS is not accurate... With the new motor boat speed feels a lot faster. But I know the prop is all wrong cause when I hit it the rpms jump to 5500 almost instantly then bounces on and off the rev limiter. I guess what I'm saying here is the prop is way too small and I don't have a clue what direction to go in with a prop. I mean the drive is buried in the water and the prop blows off without trim. I did hit it out off the hole one time and it felt like the boat was gonna flip over. Anyhow, help would be appreciated I'm already into an expensive prop the will not work.

I had an 88 setup about the same, but about 630hp. -2 lower, hull blueprinted, spinning a 26 bravo 1. 78 mph @ 5500 with 3 people and a half tank of fuel. I could blow it out easily if I wasn't careful out of the hole. I would say with that much power and the short drive your going to need at least a 30p 5 blade. I could have spun a 28 51-5300 with a lot less power.

Forgot to add the boat speed stops just below 4500 rpm but its kinda hard to give a precise point cause my gps is so slow and it pretty much feels like the prop is cavitating all the time.

What are you trimming it to?

No trim drive buried. Does respond to trim at low rpm I can get about 400 rpm and some mph. Higher rpm trim doesn't make the prop hook up any better...

Stock x dimension? You're def going to need to try a higher pitch first then maybe try a 1" spacer. But I think a 5 blade prop should be the next thing to try.

Well my 88 240 before I bought it had a 711 hp motor in it. It had the stock bravo on it, but the x has been raised 3.5 inches, and it didnt have a problem blowing out..and it ran a 30 pitch mach 4 blade. I think you could turn a 32 pitch bravo with no issues..a 5 blade might be a little harsh on that drive..esp if ya plan on leaving the water at any high rpm...I spin a 26 bravo on the boat now with a 430 hp motor in it to 5100..

i have a 1988 with 718hp 136gears bravo drive, running a24pitch bravo one prop at 5800doing 82 to 86mph . i have stock drive setup .i was thinking about putting a short drive on boat? but not shore if it will make my boat do better???? i did a lot of testing and find that i did the best when i prop my rpm to the max hp on my motor thats 5800rpm .. what is your max rpm??

Motor is 500 efi with 540 kit and pro charger. Rev limiter set at 5500. But the boat stops pulling long before 5500. My last setup was 1.36 gears stock height with 24pitch b1 4blade 76mph around 5000 to 5100. I think stock drive height is way to low cause with the old power I could trim the drive until the I joints would start singing and it would never cavitate. Kinda looked like a jet boats rooster tail. The shorty definitely improved handling in the big chop. But it's hard to say what it will do with the right prop. I have a lead on a 32pitch b1. As long as it doesn't rain I'm gonna give it a go next weekend.

Sounds like a weapon!!