[saj1420]

does anyone index their spark plugs when you replace them? i had never heard of it before but the manager at the autoparts store where i got the plugs said i should go to summit racing and get a set of indexing washers so that the electrode on the plug points straight up between the valves. is this a good idea or not?

[tmoss]

In racing, every little edge you can get counts and this is one thing that some racers do. Another is "side gapping" the plugs - you grind the electrode back and angle cut it to provide a sharp edge over the center of the spark gap - see the illustration. Plug manufacturers seel plugs this way also, but I don't have the number of the plugs. They cost more, so I just do it myself.