BT,
If the vacuum port is under the carb as opposed to in one of the runners you should be ok , with only a minor idle adjustment. Don't forget a pcv valve. This restricts flow at max vacuum so you won't really have a major leak as if it were just the hose. At WOT there isn't all that much vacuum either. If you can place the valve in a grommet in one valve cover and add a filter to the other , or leave it connected to the flame arrester. If your engine oil looks ok , I wouldn't worry about it too much. Like aero-offshore said , this was a very common occurence back in the 50s and 60s till positive crankcase vents appeared.

get a butter knife and some Ritz crackers

My oil doesn't look good. It is frothy. Problem is, after I rebuilt this engine and got it running I had the unpleasant revelation that the aluminum head was not prepare properly and I dumped significant antifreeze into the brand new engine. Then I replaced this head. So I am not really sure what I am dealing with, just know that everything I pressure test looks fine. And I have done everything at least once. I wonder how one gets antifreeze out of oil? Thanks for the verify Mo... that is kind of how I was thinking the pcv setup should be arranged. Good luck with your ps debacle.

BT

Do you have large cams in these engines? Water reverting could also cause you to drop a valve. Hot valves and water don't mix. How do you dump water overboard?

EWWWWWW!!!!!!

Not excessive cam patriyacht. They did revert with the stock exhaust. I run full length headers now and intorduce the water right at the tips now inside the boat. The other engine has clean oil and same stick. I did repair one flapper in this engine over the winter. Looking at that now to see if maybe it stuck closed or something. I'm going to put it in the water this weekend and try to collect more facts. Like, does the water come in running or sitting, how much water, what affect does pcv valve have, changing to 7psi radiator cap on the cc and so one. I can't see putting it on the stand until I know what needs to be addressed.

Thanks for the ideas,

BT