Which head gaskets do Dart big m sportsman blocks use with a 4.6 bore? Is it a 1057 or a 17049? One has an extra hole that the other does not have.

If I was going to use a felpro gasket I would use the 1077 and drill the extra hole in it. It's easier just to buy the Cometics. They already have the hole. I wouldn't use either of the gaskets you listed. Just what I would do...

With the dart block i don't think the extr hole is needed? Thats more less the question I have.

Of the two you mentioned I'd use the 1057. Dart block has both coolant holes in the end.

you use the extra holes in the block w/ the proper head gaskets(I like cometic) for extra flow thru the head.It helps fight stream pocket build up.This way here you don't have to drill your intake and run extra lines forward.

I don't beleive the dart block has the hole for the opening in the 1057? Correct or incorrect?

in the back of the block,,it appears to be there.a single hole just below the head bolt.

What hole are you referring to? The Dart block has both upper and lower coolant passages at the rear of each cylinder bank, just like the Mk4 block.

So a c5434-027 cometic gasket would be the correct ine for a 4.600 bore dart block?

That's for a Brodix big Duke head. The Cometic for a standard, conventional BB Chev head on a Dart block is the C5331-(thickness)