BORE SHROUDING TEST: 4.03" vs 3.91" Edelbrock RPM Heads Really Fit a 318? Project Mission Impossible

Only to a point, I had/ have one. Hard to tell cause it had 4.55 gears. Ran hard up to 100mph by the 1/8th mile and just stayed there to the stripe, 1/4 mile. Just not enough compression. Still fun till it spun a rod bearing.
sounds like too much gear??