I would hope you didn't gap them to 300 thousandths...Just pulled and check d my 2014 @ 10k miles. All were gapped at .320. I closed them down to .300 and chunked 'me back in. I'll probably run these for a while longer to see if new gap does anything with the occasional shutter. If not, maybe some motorcraft iridiums. I was surprised they were all consistently gapped after reading so many who found otherwise. Maybe I got a Wednesday truck
I take in you're on stock tune? What octane fuel have you been running?
What we need is a colder plug with beefed up insulators. It's coming...stay tunedI may go back to them once these NGK plugs are done. Never had a problem with them once I recapped them.
Then the spark plug debacle was on with Brisk then NGK now MSD. What we need is hotter coils.