340 popping through carb at low RPM.

Describe the pop. Does it pop with every fire of the cylinder? In other words, very rhythmic? If it does, then SOMETHING is holding an exhaust valve shut. Whether it's a wiped lobe, bent pushrod, broken rocker......whatever. The engine actually will not skip. It simply blows the exhaust back up through the intake manifold and is the noise you're hearing.
Burnt valve------------