Honestly, My little donzi is gonna go 100 if it kills me or not. I was going to do a blower but my personal goal was to go 100 N/a. When you get down to making power with a 632 you need valve lift. Bob and I have discussed this and he doesn't see an issue with it at all with the big lifters. Only thing I could see is that it's gonna be hard on the springs and I'm going to have to check spring pressure as a maintenance type of thing. It's not a big deal to me I have the tools and use to doing this sort of thing...

What type of timing chain set up are you planning to use?

What kind of heads you have? Are you going to use a titanium intake valve? Spring oilers a must. How much HP you have currently? And how fast have you bin with this boat?

Slawko/ Dart 320's. Stainless intake T&d shafts. Not sure on current hp. Has piss poor Brodix heads on it now and never denied. I've seen 95 so far. Then I added a different water pick-up cause I was having water issue the new pick-up is way below the hull and I lost 3mph.

Don't think dart 320 head is big enough for a 632" engine. Had some issues with the intake lobe on my engines that's why I asked about the titanium valves. Witch brodix heads did you have?
3 MPH that hurt from a pick up.

ok,now i understand what your goal is.a large cubic inch n/a drag race engine in a boat has been done before but it is not the norm.as you stated ,the maintenance and life of the parts usually limits that in pleasure boats.imo,a supercharged engine can get you where you want to go with a lot less hassle and better longivity,but i do understand following a dream and making it reality.good luck and keep us informed with the build.

Gotta be .937? FWIW- Bob was saying in a recent thread that the morel .903 lifter was a great piece.

I agree 110% Mike. Those little 1000 hp 522's you guys whipped up in my opinion would be a perfect boat motor that should have many many trouble free hours. Just not what I set out to do. I'm a mechanic by trade so the work to me is no big deal and there's just something about a big cubic inch motor that makes me tingle all over. My boat definitely isn't a looker by any means but whenever I tie up it draws a crowd (not that it matters to me because Im not a people person) the normal reaction is "WTF is in that thing?".

It will not be a Dart 320 when Tommy is done with them but it will have the perfect port to fill 632ci @ 6500 rpm. He's going to use the 320 cause there is alot to work with and its a very beefy head. A lot heavier than most aluminum heads if your are concerned with weight.

The .903 is a great piece but a .937 keyed lifter is an even better piece just a heck of a lot more money to.