Leaking from head bolts

451Charger said

Define "LATER" As I recall on our 1974 Swinger 318, only the end bolts on the headers required thread sealant.

Click to expand...

Early 1980’s IIRC. When I see the water passages in the deck I can tell you if it has blind head bolts or not. So yes, there are blocks out there that don’t have blind head bolt holes.