have you done a full tune up, carb sync, and a plug chop to determine going to a #78 or #80 really needs to be done?
if your gasket material is in good shape, cut it to fit and superglue it. No problems wth mine after 6months.
or, local home stores typically have gasket material that wil lwithstand gas, in 1/16th OD that can be cut to fit.