[FWB]

the extra holes on the headers are for fitting on other fe engines. 390 gt
and some 428 cobra-jet heads. the gaskets will work fine with the upper and lower holes only. with that being said does your head have these holes in it also
if so then buy copper gaskets for 428 or 390 gt. the extra holes were for factory exhaust manifold fastening due to not much material to make a seal
with the cast exhaust manifolds.

Fred