late model slant six head

They made peanut plug heads with both styles of valve cover. 75-ish-80 took the same valve cover gasket as the 60s/Early 70s ones did

I put a 77/78 vintage peanut plug head on my 74 block no issues.
As far as I remember reading the combustion chamber on 68+ are all the same but different from 67 down. And supposed the 68+ are better ones in that department