My 340 Cuda has been sitting for about 6 months now, last work I had done to it was replacing intake manifold gaskets. Spark plugs and wires were all replaced and wires are all in correct firing order. When I run the car, there is a loud popping sound coming from the carburetor. Is this a timing issue? I’m not sure if the mechanic had tweaked with the distributor when removing the intake manifold. What could I check for?

 

Sounds like a stuck valve.