Advice on stroker build with cracked cylinder

not 100% if you are getting backflow as the ling rod piston travels up before the valve closes
at some point rpm and intake velocity my get you more VE till you run out of flow (cam, heads)
it also varies with compression
Vizard writes about this- I'll see if I can find it

Because of the delayed intake closure, there is considerable piston motion up the bore from BDC before the intake actually closes. This, at low rpm, pushes some of the mixture back into the intake manifold. This means the volumetric efficiency (breathing efficiency), and thus the effective displacement of the cylinder, is well below 100 percent. In other words, a 100-cc cylinder with a static CR of 10:1 may only trap 75 cc of air. This means the dynamic CR, at about 8.5:1, has dropped well below the static CR of 10:1. The bigger the cam, the more this effect comes into play.