Damn it.

I appear to have a short-nose crank problem after all...as you can tell.

On the upside, apparently Miatas are really easy to work on, much simpler than any Honda I've touched or an S-chassis. I spent a total of maybe 4 hours getting everything taken apart, working only from miata.net "garage" section printouts.

1.6L Grainger manual is in the mail.