Going through a similar thing with the 327 in my 54. Occasional spit back through the carb, usually on light throttle. I have no sense of smell (mighty useful sometimes)so I can't speak to the old gal's fragrance when she blows off like this.
I kicked in some more advance and it's almost cured. So I'm going to try more of the same.
Might be worth a try for you?
Christian
