You've heard it before ?

3.40 x 4.125, makes a swept of 613.72;That's
~9% more than a 273(562.2), and
~94% as much as a 318(652.27).
that's a lot, eh?
Huyp, that will make, making cylinder pressure, a little easier. And you only have to cut ONE head, and it doesn't mess up the valley seal,lol.