Guys, I have rebuilt everything on this boat. I even built the engines. I consulted Dennis Moore on the build and he sent me a build sheet to go by. If anyone has any questions just ask away. I just recently turned my 420's into 525 sc clones by adding weiand 174 superchargers. And Yes rhey did fit under the hatch by less than an inch. The boat is much faster and quicker off the line, but I have yet to get the carb jetting down. Pics to follow and results. Although I did get it up to 67 on gps so far with a full tank and a dirty bottom.

Joe

Offshoreratboy,

I have the clones also, but putting out about 560HP per side. Last time out the starboard engine really started throwing oil so I put her away until I can get back to the fix. I will be doing a new leakdown when I return next month. If it looks good I will just try to fix the seal that is leaking. If its bad I will pull both engines and rebuild. I am considering going up a notch on the blowers to 6-71 with my single 850 Nickerson Carbs. I want to get around 650-700 per side and take it easy on the drives.

Take it easy on those drives they are really only rated for about 500 hp. What kind of speed did you get out of your rig? Sure is hard to get these big heavy boats to go fast...The real reason I supercharged was to get better fuel economy at cruising speed. Before the upgrade I was burning 1.2 gal per mile! Thats sick! I could only get 36 mph @ 3500rpm. Now I get 44mph @ 3000. I have mechanical secondary 850s I marked the throttle where the secondaries come in. I can now cruise @ 44mph on the primaries. The next thing on the list is hydraulic steering, this thing is a bear at high speed.

did not have time to check the link for GM crate engine info. Sorry. I'll do it tomorrow.

Brian- 86 357 KAAMA. In pieces, getting repowered.

I have an 89 with 560 or so per side. I've made significant changes all over. I'll post some pix soon.
Rick

I have seen 72 GPS at 4800RPM I am unable to get the full 5500rpm yet. I will not be back to start again for another two weeks.

Can we get a list going with power/ speeds/ drives ? Just for the 357s. I think it would be interesting and helpful for people to see how their combinations compare, especially someone like me who hasn't yet finished their power. Thanks

Shaun- 86 357 with approx. 650 hp a side on bravo drives. I have been 75 on GPS, cruises at 50 mph at about 3200 rpm.