Fyrestorm

I just put iridium plugs and its still missing. I used the correct plugs, My owners manual calls for AC Delco 41-110 and that's what I used.

A few weeks ago my 5.3 started misfiring during acceleration or when a load is placed on it. It idles just fine with no issues. With 140K miles I decided a complete tune up was in order. I replaced all plugs, wires and all 8 coils with good quality OEM parts. The plugs and wires only had 40K on them but I decided to replace them anyways. After all that it's still misfiring. The computer hasn't picked up on it as it has not thrown any error codes and the check engine light hasn't come on. All 8 spark plugs look exactly like this. The center electrode is almost gone, its now smooth causing the gap to double in size. They only had 40K on them. Any ideas what would cause the misfire to continue? Any ideas as to why my plugs look like this? Are the problems related? Appreciate any insight.

When I re installed the ebrake cable onto the shoe it wasn't pulling on it. So, I want to say no. I could move it back and forth.

I have a 2011 Silverado, Yesterday I replaced the shoes on the rear drums. Everything seemed to go well until I tried to put the passenger side drum on. It wouldn't go on for the life of me. I had to adjust the wheel until there was no threads left to get the drum over the shoes. And, when it went on it was tight. I took the entire drum apart 3 times and put it back together in case I was missing something. It was the same every time. I did the drivers side and it required no adjusting and went on fairly easy. I drove it around slowly to test and I can hear that brake. I've tried backing up and hitting the brakes HARD to adjust but it still makes noise as I drive. I've done this about 5 or 6 times. It sounds as if its just barley pressing against the drum, like a dragging noise. Both brakes worked completely fine prior to this. Anyone have any ideas or advice as to what I can do to eliminate the noise? Is it possible to adjust the passenger side after I had to screw in the wheel completely? I appreciate any insight or advice