Plannign to go to a 350" 355hp ZZ4 crate motor, gona run headers, holley carb, thru hull.

Now the boat had through hub exhaust on the 4.3, how loud will through hull be on it with a 350? Strait through, not the silencer tips. (Corsa by the way)

What about mounting them right below the waterline so when the boat is not on plane, it is quiet, (for 90db checks) and when running i get that nice V8 sound. Will I have to worry about Reversion??

The zz4 is not designed to be a marine motor. It does not have the correct cam, bearing or piston clearance. I'm not sure, but it may not have forged pistons. This would not be my first choice for a marine engine. That said, I'd guess that it'll be quieter than the V-6. The 4.3's really rap. Yes, you can move the tips below the water line. Be sure to use a good flapper and have some extra rise to the system before turning down.

acctually the cam it comes with is a little mild for the heads it runs better with the hot cam and switch out the stamped rockers for allum. 1.6 rockers than it pulls 425hp @ 6000.
I agree with cord though not a boat motor, but you never know. may be a hot setup. you'd better ask someone who's tryed it. If you need one let me know I get them cheap.

I talked with the Factory 1 team Mutual Fun, he said he has been doing ZZ3 and ZZ4 swaps since 1991. The first boat got a ZZ3 and 125 shot of nitrous, not been taken apart ever and still runs fine.

Just Once, How Cheap??

The only thing I would worry about with a ZZ4 engine would be the exhaust valves. Upgrading to inconel valves would be mandatory!

What about Manley valves??

Now how many extra newspapers are you going to have to deliver to be able to buy all this stuff ?

its not the news papers to be delievered thats first but getting the job first.

I'd like to hear some view points on that last question... Inconnel exhaust valves or manley SS exhaust valves? What's the diff?

BT

Hyper, just come to my lake with me next summer and I'll pay you to wax the Spectre, top and bottom and clean the ole lady's pontoon, and I'll even let you drive the Spectre when your done, now is that a deal or what ?