So my motor blew out the #4 spark plug ( pain in the hind end to get)
i got the fix kit from NAPA (3rd time using it on this motor different cylinders) now i have a misfire in the #4 cylinder when i put it in gear. It has a coil and have even swapped around coils to test. Misfire stays put I am at my wits end with this and can not find any solutions.

 

Did you check the wires going to the COP, my friends 6.8 V10 popped a plug and it had the same problem, there was a nick in the wire that went almost all the way through going into the COP and it was just not making good enough contact causing the miss fire.