Re: 1983 Wellcraft Restoration Project: Pulled Engine
I advise putting these engine questions in the I/O and inboard forum-but here goes.
If the deck is fine, why deck it? Before you do stuff like that, think about why you are doing it. "decking" the block is done if the deck surface is uneven, or if you are trying to achieve some specific compression ratio. What is your current deck height? What head cc have you got and what is your compressed head gasket thickness? What is the compression ratio of the engine stock and what are you trying to acheive? If you don't know the answers to those questions, don't go telling the guy at the machine shop "Take the deck down to five thousandths" .....You could end up with something like 11:1 compression that will detonate like crazy on pump gas. And never live in such a low RPM high load application as yours.
Now, when you deck the block, you also throw off your pushrod/rocker arm geometry. And depending on how much was taken off, your intake manifold may have to be milled too. This opens up a can of worms.
If you take the block to a machine shop, have them dip it and check it for cracks. Then they will be able to tell you what it needs. If any of the bores are pitted, they may need to bore oversize, which will require new, oversize pistons. I have also seen more than one marine engine used extensively in salt water that once "cleaned up" in the hot tank was pitted through the block from salt water rust. Not worth fixing.
Do you know someone knolagable about engines that could come look at it and see what it's like? I saw water in a couple cylinders from sitting or something- that may be cleanable with a ball hone.
Some of the other things you ask about? Well, closed circuit cooling (fresh water cooling) is great for the longevity of the engine. MSD igniton probably won't provide any better performance than a properly working stock inginiton system, from what I have seen. Others may disagree.
Listen man, I'm not trying to discourage you from this venture. But what I see is you wanting to do things that won't work well with the overall combination.