Also like has been said, vacuum slide carbs and long intakes don't play well together. That air filter is the worst setup there is as it allows air across the face of the carb at speed and jacks up the vacuum signals the carb sees. You need an airbox on that carb. Homemade intake sealing is suspect and no telling what gaskets. Check for intake leaks. Is that jb weld piled all over it? Probably fighting a cracked intake. You'd be better off with a butterfly carb on that intake. Often those carbs need the airbox to hold the carb on. Only thing I see is the boot. Is it banded? Long intake, jb weld, and no carb support coupled with some vibration is a recipe for intake leaks. I'd try and source the proper intake,carb, and airbox and get rid of that mess that's on there.
