gap for plugs - MSD box & dist.

Oh, the ignorance........

Gap erosion is a very bad thing because it leads to misfires. This is one of the reasons that Plat & Irid is used for electrodes. As well as having a very high melting point, they are also very hard metals. Erosion is slower, making for less misfires & therefore less emissions & better fuel economy.

Spark mark is real and it matters.

If you don’t check your plugs until they start missing that’s not a plug problem.