[Mike C]

I quote it often, but an old hot rodders addage is that 90% of carb problems are ignition. Not to say you don't need to work on your carburetion issues, but you should start by sorting out the ignition. It's hard to diagnose over the internet, but it sounds almost like a plug wire has come off the distributor cap or a plug. It could be a wire has burned on the exhaust as well and is shorting there.

HEI conversion would be my chosen way to take care of ignition woes. Skip White has complete distributors for $50. Get an HEI wiring pigtail, 12ga wire, and a spade connector to plug into the unfused ignition terminal on the fuse box. Run 1975-82 Corvette plug wires which run underneath the manifolds like the stock points wires but have the correct HEI terminal and boot.

Do a search here on HEI conversion here on the board. Otherwise, get a new set of points, condensor, cap, rotor, and wires and replace all the stock ignition pieces.

Only when the ignition is 100% can you hope to make any headway with the carburetor and any minor adjustments it may require.