The question is, now what? I pretty much have a handle on the most I should do (complete top end overhaul). What do you think is the least I should do? Compression was 149/139/145/151 psi last I checked, which I'm under the impression is OK, so I feel like there's no need to turn a big project into a giant one...
It seems to me that to do the job right, I should at least replace the cylinder block base gasket, but then that means replacing the rings and the hassle of getting the block back over the pistons. And my Haynes manual says if I do that, I should have the bores "glaze busted". Sounds like potential headaches.
Also, should I do something about cam chain tensioning bits? I have the classic chitty-chitty-bang-bang slapping...
Suggestions/Experiences?

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Not sure how "classic" that is, you should not have any. While you have the tensioner off, you can clean it out to make sure it's working freely, then just make sure it goes on and is set correctly. I have seen some tensioners that were locked into place when they were installed, so there was no chance that they were going to be able to take up any slack that might occur.

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