Sorry, I wasn't aware there was a hole/opening in the bottom of the choke pocket that would require sealing with a gasket. The ones I have dealt with are like your '74 version, open on the one side. Is the hole in yours a factory feature, or is it possible it just rusted through? I'm trying to imagine why they would want exhaust gas up in there gumming up the works by allowing carbon to build up on the choke's spring. Guess we'll have to wait until someone else chimes in that knows this type of manifold.
