My engine developed a shake/misfire in the middle of a drive

The headers are not the problem, poor plug wire routing and retention is. I use 135 degree custom/builder type Taylor plug wires and wire looms that bolt to valve cover bolts. Preferably the type that can squeeze the plug wires and not allow them to rotate after you have precisely arranged them for clearance.
I have only burnt plug wires when not loomed and spaced correctly. Yes I learned the same way as you have SEVERAL TIMES.
I am not trying to be a condescending butt munch, my apologies if taken so. I for what ever reason get extremely irrational and irritable when poor craftsmanship is exercised in routing plug wires, fuel lines and engine bay hose and wire routings. Many people think those fancy fifty dollar looms are a waste, yet two cheap plug wire sets will set you back forty to eighty bucks. I see them similar to brakes you just need them or its a wreck.