To do that in the engine would require a LOOONG reach dial indicator (read: very expensive!). Or a 1"indicator with a looong extension in place of the standard tip
I wouldn't bother. It's clearly a purple solid cam very much likely the one referenced above. Between the lash, and the typical 1.5 ratio mopar rockers measuring closer to 1.4, actual valve movement of .440 is about what i would expect.
You have years of good performance with the settings you've got. I might try 20/20 for fun..... but I wouldn't expect anything to feel different at all. i think just about any solid can run 20/20, at least in my experience.