Friggin plug wires! Mopar Performance P4529797

Two things to remember about high tension leads is:
- what is the insulation made of
- what is the conductor made of

Silicon insulation is very good as it has very high dielectric strength AND high temperature resistance.

Factory & many aftermarket wires use a carbon/graphite conductor which can & does break, causing sometimes maddening intermittent faults. They also have very high resistance which reduces the spark energy that gets to the plug tip. And they are usually cheap, so you get what you pay for...

The best conductor is spiral wound copper or s/s over a graphite core that supresses RFI while at the same time being low resistance & not robbing the spark plug of energy.
Solid copper core is also good, but causes huge RFI interference.