MCM 165 (470) cylinder head help

I removed the cylinder head from my '87 MCM-165 in order to troubleshoot a vanishing coolant/steam at start-up problem.

When I removed the cast iron coolant tank, I saw coolant down in the #3 and #4 areas of the exhaust manifold. That confirmed my suspicions.

When I started cleaning up the cylinder head, I encountered a lot of rust around the #4 exhaust port, which I'm sure is common. By the time I chipped away the layers of rust, it became evident that the exhaust port wall will be pretty thin and the gasket mating surface in need of resurfacing (if possible).

So, I started looking for rebuilt heads, but I need the casting stamp in order to get the correct one, but guess what. The letters on my casting stamp are totally rusted away.

Here are my questions:

How thin can the #4 exhaust port wall be before I'm risking doing this all over again really soon?

Do machine shops normally resurface the exhaust and intake mating surfaces?

How can I figure out what casting run I have since I can't read the numbers on the outside?

I've got some pictures. I get a link on here ASAP.

Thanks,
Nate

Re: MCM 165 (470) cylinder head help

Pictures: http://s622.photobucket.com/albums/tt308/natemoore_2009/?albumview=grid

Re: MCM 165 (470) cylinder head help

I had questions about my head (pitting in #4 chamber), so this is what I did: Asked the local Mercuiser dealer where they get their heads done. Took the head down and talked to the machinist. He had experience with 470 heads and answered all of my questions. Most of the answers were "no problem" and "we'll take care of it". It wasn't and they did, worked out fine. Good luck

Re: MCM 165 (470) cylinder head help

Yes, they are getting thin. From rust and heat.
You can expect it to be next to fail, but since you have the cyliner/piston/ring problem to go with it. Just add it to the price.