Intake leak

[shatar4]

I have a new intake that I'm put on my 340 and it seems I have a leak in the two back cooling ports. I know there is ports in the intake but not on the stock heads. What can I do to seal these off so I don't get anti-freeze everywhere? Thanks

[Strawdawg]

take the intake off and seal the ports with some silicone on the various mating surfaces-water ports

[jimynick]

take the intake off and seal the ports with some silicone on the various mating surfaces-water ports
 . Some of the old-school boys used a piece of thin (.010") brass shim stock cut to cover the port to go along with that silicone. When you've got the intake off, check on a piece of plate glass to make sure it's flat. Any more than about .002" (use a feeler gauge) discrepancy might require a trip to the machinist to level 'er off. Some times, a thicker gasket can be gotten away with.