Heck if I know. I've always run stock iridiums and one set of coppers and never had an issue. I was just bustin ya for the mad reading skillz, lol...
Still thinking there's a bad wire(s) and/or they're in the wrong order somehow. I know we always hear "I checked the firing order twice and it looks fine", just to find out that 3rd time looking shows someone f'd it up anyways.
StockGt03- When you change the wires make sure that the wires for #4 and #6 (the middle and drivers side in the rear) aren't resting against the O2 sensor or the manifold as that can cause issues as well.
