['ol Pinion head]

Originally Posted by Hedgehead

Thanks John. Went and looked hard at that spot, sorry but I cant see it.

Kenth these are screw in rocker arm studs if that is what you mean.

Kenth is pointing to the possibility of the heads originally having press in studs which would have bolt down guide plates versus the style of guide plates that were used under factory screw in stud big valve heads.

FWIW, there was a local fellow in my area in the early to mid '80's who built multiple dozens of pairs of "gimme" '68-70 small valve heads into big valve high compression screw in stud heads. Each time, he carefully ground the casting numbers off, occasionally stamping other numbers on the center exhaust ports. Same fellow also heat treated, shot preened, and rebuilt a BUNCH of '58-62 rubber rods and sold them through local Trader publication.