Make sure that any vacuum passages in the carburetor flange aren't blocked, and that there's no way for outside air to get drawn into the manifold. There's nothing particularly magical about gaskets- - - -I've made dozens of them with nothing but an X-Acto knife and a few brass cartridge cases for hole punches.
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!