Capping a heater outlet in manifold

[XakEp]

My new dual plane manifold has a provision for a heater line, but I'm using a port in my radiator for coolant and do not need the manifold option. What should I use to plug/cap it off? Its an Edelbrock Performer on a 318.

 

[briankaplan]

Just go to the hardware store and get a couple metal
pipe plugs. Put them in with teflon tape or liquid from
a tube. Just don't tighten to tight to crack manifold.

 

[GoodysGotaCuda]

you need 3/8npt plugs, i run teflon tape on them as well