EQ heads, Chevy rockers and what studs?

I was thinking of the Crower backset trunion rockers as a fix
or there are studs with 1/2 inch lower thread which could offset without welding- have not tried it in a magnum but have used for repairs elsewhere
I'll have to check out the Hughes and Crane suggestions
I usually use + length valves in SBM and Pontiacs and others with shot spring heights