Thanks phragle, i'm not a Chevy guy so I'm learning all these things about these Gen IV, V & VI. A 468 with some good oval ports was my first thought but a buddy of mine has a 174 he would sell me pretty cheap that's why was thinking maybe just the blower on the stock short !

What your facing is the cast crank (in the 330 hp 454 vs. the forged crank in the 454mag /502) The forged crank is much stronger and will take much more abuse than the cast crank you have.

in the marine world a cast crank shouldnt be spun more than 5000 rpm and 500 hp is really pushing it. many have done it, but the safety margin just goes right out the window. Spend some time reading the various 454 threads on here and you ccan learn/figure out quite a bit.

Like to try that 23 mirage plus on my Mach 1. Wonder if it will get me to 70....... My 23 mirage gets me 69.6

When I bought one of my boats it was supposed to have 525sc's -- after losing a cam lobe I found out that they were actually stock 330's that had been bought as a long block and all the acc's and blowers were used to dress them... They ran fine at around 5 lbs boost for the year that I had them. based on speed I'd say they were putting out around 450 hp ( had chillers also) I don't see any reason not to do it as long as you run good fuel and watch your timing.

As far as the 330 now -- did you say that timing was at 8 degrees? Initial or overall? what is the overall timing? Should be around 28 in order to get any power out of it at all....my buddy had a 24' formula with a mag and it would run 58 mph -- it was a great boat...

Take the beer of the boat and you should hit 70 no problem...

Whoa whoa let's not talk crazy now.

Yeah that's what I've been learning phragle, but to do what I want to do to it would probably only take 400 - 450 hp I'm guessing , The Supercharger thing I think would be cool because of the bling factor the boats really clean and with a few things like that to it I think it be pretty cool looking and would be easy, bolt on !! I've also been looking at a few scat an eagle rotating assemblies, reasonable price little more work though. !

That's interesting and good to know delsol About them 330's with Superchargers ! Timing is set at 8 deg initial, it has a thunder bolt IV with a V24 modual I believe in it ! I never checked total timing I just assumed it was correct !

I had an 89' 242ls with a 330hp merc in it, ran 56-58 depending on load witha 22p 4 blade bravo 1 prop on it all day long. There's something keeping you from running faster, hook in the hull, water logged, trim issues, low compression, something. Find out what before you add a blower, you may be suprised at its performance when set up properly. I loved that boat, rode amazing, my only complaints were it's slow to get on plane and is way too sluggish when the tank is filled all the way up

Thanks gmgearhead, there's something definitely wrong I'm just not sure if it's me or it yet ! LOL When I tryed a 22p 4 blade I could only get it to RPM 4000-4200 maybe I needed to trim it a lot more than I did ? This boat takes forever to get on plane also, struggles bad but that was with a 21p 3 blade ! The 22p was way better out of the hole but again rpm'ed low. I want to build a new motor for it, just was comparing price on a supercharger on the stock 330 or a whole new 496 ! The thing is i bought it late in the season and only had a month to test & learn !

Honestly if i was you i would at least rebuild what ya got, even if it's just throwing a cam, set of heads, and intake/carb on it. You can make 450-500 hp that way and as long as you don't spin it much over 5k you'll be fine. Put some arp rod bolts in it and call it good. And yeah no matter what i would run a 4 blade on it, it's just too heavy of a boat to dick around with 3 blades, the cruising & planing is SO much better with the 4 blade on that hull