Real World Flow Differences 2.08"/ 1.74" Valves vs 2.14"/ 1.81" Valves " Pictures Added"

My heads have had a serious amount of porting done and removed the short side radius (pushrod protrusion). The side wall is now straight all the way in (offset rockers and epoxy) and the roofs are raised .350".

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Obviously your heads are far beyond what is typically done with factory castings.
Therefore, I wouldn’t consider whatever results were gleaned from valve testing on heads that weren’t configured like what you’re working with to be valid.

In my mind there’s only one way to know for sure what a larger valve would do in those heads........ and that’s test it and see.

I see the questions as........ how much more flow would you need to see to make the bigger valve worth the effort?
And....... does that seem like a realistic expectation?

From the configuration you’re describing, I’d expect a bigger valve could be worth fairly significant gains.
I’d probably go bigger than 2.14” myself.