Rebuilding my '97 Vortec, and these head gaskets only have 1/8" openings where the top coolant passages are, I'm afraid it's going to overheat and crack the heads. The gasket hole for the lower two coolant passage triangles seem undersized as well.





Am I safe to enlarge the coolant passage openings? Any history of issues with doing so?

And what about the oil passages? It can't be bad to allow for more flow, can it?

Did fel-pro design them to be exactly this restrictive, or is it ok to modify them?


Thanks in advance.

 

The shop I had the machining done at says to leave it as is, so that the coolant will flow in the right direction... as well as leaving the oil passages alone, they're apparently "sufficient."

 

ooohhh shiny lol. id agree. if you do dont touch the area around the cylinders. even though the holes are small theres more that one youll be good