Rebuild required?

'77 Martinique, Escort 351W, 800+ hours, never been opened up to my knowledge.

Late last year I rebuilt carb. Got it back on boat, but never got it running right - always seemed way too rich with lots of black/brown exhaust. Anyway weather was turning cold, and battery was dead so I just winterized engine too wait for spring.

Well it's getting to be spring in Michigan now. I decided to pull heads and take a look inside engine to check overall condition.

Lots of black carbon build up in combustion chambers - probably from over rich condition.
Some rust in upper part of cylinder 8 - head gasket seepage maybe?

Anyway my question is are there some easy steps I can take to fix things up or am I better of taking somewhere for a complete rebuild at this point? I'm always keeping my eyes open for a newer 80's 2001 Nautique and would like to upgrade. I would rather not sink a ton of cash into a reubild if I can get the boat functional myself.

Here are some photos of the head and cylinders.

Bob is right on! Take his advice. My personal gauge as to compllete rebulid or not is the amount of ridge at the top of the cylinder and I do not see any ridge on yours - unless of course a rod is knocking which requires repair ridge or no ridge.

A soft wire wheel on a hand drill makes quick work out of cleaning the piston tops. Don't scratch your cylinder walls.

In addition to having your heads rebuilt, now is a good time to replace your timing chain and gears.