Took my 64 nova out for its first ride this year. Was running fine and then started popping out the mufflers. Last year it did the same thing and I had to replace the 4-Pin Ignition Modules. Did not have another issue all season here in Michigan. What could be causing this issue. I have a new dizzy and all new wires - coil and plugs installed last year. Could it be the fact I am still running with a voltage reg.