Not trying to intrude on this post but I'm in the middle of building a 572 C.I. B1 original head pump gas motor now with a KB wedge block I got from Tim @ FHO last year.
The heads were used and came with a set of Jesel paired shaft 1.7 ratio rocker arms, I had them freshen at Slawko and still need to buy the pistons, solid roller cam and so on. I'm not sure which carb size I will run on this motor but I will test several different ones, 4150 and 4500, and see what it wants
I'm hoping for 900HP on Oregon pump swill