If it's NOT equipped with electronic ignition, there'll be a rectangular ceramic block about 3 inches by 1/2 by 1/2 or so with two wires attached, and located on a fenderwell or the firewall. That'll be the ballast resistor for the ignition. When ya go inspecting it, be careful, they get hot as hell with current applied - that's why they're ceramic. And don't lose the insulator gizmo if it comes off - that's what insulates it and makes the thing stay in the bracket on some. And check the wiring and connectors for deterioration because the heat makes for bad connections and crumbly insulation that'll give the same sorta symptoms.
Anyway, when these things go south, the symptoms perfectly mimic fuel/carb problems. I gained this valuable info after putting two 4 bbl carbs on a 72 Plymouth 440 in one afternoon once upon a time because it would only idle and wouldn't take any fuel, only to have a drunk neighbor toss me one out of his damn pocket, no less, and instruct me to install it. I thought he was drunk, and stoopid to boot. I was right about the drunk, I was wrong about the stoopid. Thing fired right up and ran like it oughta, and I've witnessed the phenomenon many times since. Said he kept one handy 'cuz they have a habit of puking. He drove a '73 Goat pickup with a 440 6 Pack, BTW.