Electrical, popping noise

[Stringer]

My 72 has a '90 350 TBI, 700R in it. Runs pretty good. I'm embarrassed to say that, for the last 6 months or so, it's making a popping noise...sorta' like little firecrackers and it's coming from the distributor or thereabouts. I'm embarrassed cause I haven't taken time to look into it until now! Runs fine - only makes the noise when it's hot. Audible in the cab...standing beside it.

New spark plug wires. New cap and rotor. If I'm testing correctly, my ignition coil is bad. Would that cause such a noise? Also, when I finally changed the cap/rotor this weekend (and they didn't look THAT bad), there's fine surface rust under the cap. I don't see any evidence of arcing, there.

As I always say in my posts, I'm a wannabe mechanic. I'm trying to learn, though. Any thoughts?