318 head flow

This isn’t a slam..... and you’re using a different bench...... but I think I could get to 210 with a 1.88 valve 360 head with about a 5-8 minute bowl job/pinch tweak.
I’m “sure” I could with a 1.94 valve in it.

I refer to what you’re doing as a “science experiment”...... and I’ve done several of those myself through the years.

One other thing.....
This could just be the camera used, because I know it does the same thing on pics I take....... what I assume is the “finished” intake bowl “looks” too small for the valve.

Any measurements?