Large valved 273

I've been working on this issue for the last year or so. With top ring locations being what they are typically, you're gonna be limited to the high 400's, or maybe right at .500" for max lift. It depends on the exact piston. This limit is for a stock deck, and the top ring location is the issue.

If one were to do custom piston, and would move the top rings down about .100", then you could push up close to .600" . Probably no ideal to move the top ring down but that is what you gotta do for that matter. Egge might be able to do that; dunno if you could just ask for the ring groove to be machined lower. It would depend on the basic casting.

As for the valve size and flow shrouding... sure, you would not get max possible flow from a 2.02" valve being by the cylinder wall notch. But I would expect you to still get more flow that way than with a 1.88" valve and no notches.

Turbo or super-charging makes a lot of sense.