Does carburetor accelerator pump squirt fuel into the carburetor venturi when you pull back on the accelerator rod/cable at the carb?
Rochesters have a fuel bowl float made of composite material that over time absorbs gas and rides lower in the fuel bowl when full failing to shut off the needle valve causing excessive fuel in the carb.
Also there's 2 small plugs in the bottom of the fuel bowl that sometimes leaks fuel into the intake manifold. Usually the symptoms of those problems is engine dieseling after shutting ignition off.
We had an 84 coach with the 454 and the engine kept missing out and finally shut down. Found high voltage had arced through the rotor material grounding out on the steel distributor shaft. Replaced rotor and all worked well again.
I highly recommend crankshop1000's advice to check for a lack of fuel, one step in the process of elimination in finding your problem...
Best of luck and keep us posted...