I am totally confused, going to put new plugs and wires in a C5 LS1 2000, stock, went with the ACDelco's, I am finding plug gaps from .40 , .50, .54, .60 whats right some say that GM changed the gap? That the gap set on them out of box is right? So whats right

 

Well went with .40 on the plug gap yesterday, and Thundervolt 50 plug wires by Taylor, I must admit it it does run smoother, but found the battery had a dead cell, so new battery to day.

 

I've got admit with the new plugs set at 40th and the Taylor Thundervolts wires the LS purrs, and has a smoother idea.

 

Plugs are never pre-gapped at the factory. You should always check and gap the plugs for the specified gap for the vehicle in which they are to be installed.

And never apply pressure to the center electrode.

 

When I had a repair shop, I was amazed at how many plugs came out of the box with the correct gap. Invariably we always made sure they were set to Mitchel Manual spec.