David Vizard bench flows a BBD 2bbl
When DV mentions 'stroking' the 318 crank I think he's only trying to get the factory piston to zero deck height, that's it (0.030"-0.080").
So, in my mind he'll be using OEM pistons and probably selecting the lightest ones he can find from a pile of shitty cast 318 OEM pistons.
DV's difficult to watch but has an undeniable genius, his guesses (on flow bench leakage) are probably better than most people's hard facts.
I'm tuning in, might actually learn something.