Dropped a cylinder

Hello,
So I came home from work the other day and when I turned the car off it clunked hard and backfired out the dual carbs. And smoked out the hood. Now she runs awful and #6 isn't firing. It is getting spark and the spark plugs firing but no fire. Now this has happened a couple times where it clunked stopped but this time it was worse and the cylinder no longer works. I'm thinking valve got stuck and bang but I don't know **** from Sunday I'm still a newb I'm still learning.

1974 dodge dart with a 75 slant from the factory. She was a late bloomer. Has the offy dual carb on it. Nothing crazy other than that. It was advanced 4 degrees cause the offy instruction told the installer to.