1965 Valiant 200 convertible (minor project)

The block date code indicates it's a '80 model, as well as the 0225, if that is what is stamped on top of the block surface behind the coil bracket. I'd pull the valve cover and replace the PCV grommet if it's hard. That way you can also see if it's a hydraulic cam or solid cam. If solid (has rocker adjusters), I'd check and/or adjust them as necessary.

Is "1490" the block date code? Maybe Sept 14, 1980?

And the "330" doesn't mean a "30" forged crank block like someone posted on another forum?

That would make more sense than a 1979-80 head on an earlier forged crank block.

Curious. Seems to be hard to find good info on the late slant six stuff.