Build a Hemi      

It’s not just what parts you buy, it also has a lot to do with how the engine is prepped and assembled.  I have seen stock parts that are abused over and over last for seasons, and I have seen engines with the best parts die within a few minutes.

"bulletproof" is just an imaginary word in engine building.   its a all in the prep work. and it must be CLEAN .  take your time. do it right and have fun. thats what its all about.

I'd like to run on pump if at all possible, and realistically I've seen motors for ~15-20 that produce that level of horsepower, and yeah I know it's all about the assembly. I wouldn't be doing that myself, I'm not that handy with a wrench and would HATE to do something wrong and flush that much money down the toilet.

As far as the pump, yeah I'd need to put a scoop on it, but the internals should be good to go. Maybe change the impeller...yeah that too.

Btw, I'm thinking like a 572 or something, stroker/rat motor for it. Should be a ton of fun once it's all together.

Thanks for the input so far

  build an LS2 with some good heads, like L92s stroke it to 402,put a mild cam, (228-232) run corvette belt system and put an A&A supercharger system on it. We make on a stock LS2 with a cam sometimes in the 550-600 rwhp. So on a 402 we see 650-700rwhp. Or get the big boy swim gear on and step up to an YSi blower for 700+..

the youtube video on this site gives me a boner

http://www.proformanceunlimited.com/specs/572_750.html

All I kept thinking is STFU and start the damn thing already. 

572/750hp you can get 750 hp out of a 496 stroker. i believe a 572 block alone is 13 to 15 k. also i thought you had the green yellow red gullwing? did you paint it blue and white?

Na, LS motors make low end torque, you have to look at the weight savings i think. What dose a stock jet boat 454 make for power and tq?. i checked a 1974 454 for a jet boat made around 290hp 410tq, and some made 320hp 430tq. But at what weight? An 2003 SS truck 6.0 made 345hp 380tq, now that doesn't sound like a lot, but i put a BBC head on the scale and its about 73-76 lbs, an LS head is 34 lbs. So both heads and intake of the LS is about the same weight as the BBC head. So ...Less weight...Less weight to push in the water I would think ( Now I'm still new to the jet boat world but been a car and motor guy for a long time) you wouldn't need MORE torque with less weight. So I have seen and a pull out motor from an SS truck go for 1200$ with harness and computer, get some log manifolds $700+, if you pull an Chevy out you should be good for the mounts some changing but there not too different on the sides of the blocks but people have done it. Stick a 224-228 114LSA cam and comp 918 springs in and that 345hp is bumped to 385-390 and tq stays, (we seen it on the dyno, a truck we did made 330hp 320tq at the tire). With the fuel injection it wont have a BBC apatite for gas. And if you wanted to BOOST it you can bolt on a 200cid Whipple for your low end, out of the hole power.. thats just my two pennies, when my BBF dies I have a 6.0 i getting ready.

Start looking for a 10-71 and some aluminum heads. AS a rule the bigger and badder the shorter the life span