The only head gaskets I use sealer on are the .023" thick steel shim type we used on high performance Chevy V8 engines, the ones made of a single piece of embossed sheet metal. Those gaskets benefit from a brush-on non hardening sealer like Permatex Super 300. The sealer is there to prevent seep coolant leaks, not to assist in sealing compression or combustion gases. I don't think I've ever seen that type of gasket made for a stovebolt six.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!