I own a 63 that I recently discovered an ignition circuit interrupt problem when activating the headlight switch between the park circuit and headlight circuit. Both the headlight switch and ignition switch are original and I've read where this might be a problem. I first noticed a tach signal interrupt and a noticable missfire while the engine is running. A couple times it's even shut the ignition circuit down completely and killed the engine. I'm running an MSD 6AL, High Torque mini starter, HID headlights on relays for both low and high beam. All of the engine compartment wiring is new. Am I overloading a 46 year old ignition switch? Wondering if anybody has experienced this before and what a possible solution might be. Thanks in advance.