906 head capabilities?

“In the context of this thread”, and relating to the heads the OP is using(Victor copies), the heads use valves that are roughly 3/8” longer than factory heads.
The rocker shaft saddles are relocated accordingly to accommodate the longer valves.

If you removed factory heads from an engine that had the correct length pushrods in it, and bolted the Victor type head in its place, the engine will now require longer pushrods……..and not just a little longer.

The same situation is also true with B1, B1-BS, Bulldog, Indy, Chapman stage 6(original stage 6 use stock length valves), or TF heads.