Gratuitous shiny head pics......

These heads weren’t very expensive when they were current and you could get them from MP.
Like $600/ea-ish??
These were only made because of the need for the castings for S and SS.
These are the legal replacement heads(I don’t think the Ede made NHRA head is legal for MW combos).
But, these 518-M’s are no longer made.

This set is also from the last batch made, which are generally considered the best ones.
However, in typical MP “it’s always something” tradition...... the last run were made with the chambers several cc’s smaller than the legal size for S and SS, which is a big pita for those guys to deal with.
Didn’t matter at all for this build.