Dericks
the cam according to the previous owner is the 484 lift
I can only assume the distributor is the stock mopar, there is no identification on it.
If you adjusted the idle mixture screws properly I would look at the possibility of a new power valve problably in the 4.5 range. That cam generally doesnt pull much vacuum at idle. PV's can blow out on some carbs to if they backfire etc.....The carb doesnt have a metering block in the back does it?