I have a chance to get a set of Big Block Chevy 454 MARINE
heads for a good price. These are oval port heads and they have the word " marine " stamped on them. My question is can I use these for streeet aplication or is there something about Marine heads that is different ? The heads are GM part number 3986136

Thank you

You can use them with the correct Fel-Pro gaskets. These heads have very large waterpassages in the head to block transfer area.

They are not the small intake port like the trucks have. These are more like the early port sizes.

I just won a new set of rectangle port 502's on Ebay. Gotta go pickum up tomorrow.

"These heads have very large waterpassages in the head to block transfer area. "


Can you tell me what this means ?
Will I get better cooling as a result ?

Thank you

No, the gasket actually closes these monster holes up. Otherwise you get internal coolant leak.

Thank you