[Trevor]

I just measured my backing plates and mine have 11/16" holes. My truck is all original, and when I took the factory cables out they still fit nice and snug.

LMC and other companies are out of touch because too many just let it slide and just modify to suit those wrong parts ...

Although I could do more, I'm constantly letting these companies know, the other day I wrote Amazon for a clearly wrong set of reviews for a radar detector that isn't even out yet, they wrote me back and 2 days later the error was changed. I wrote Google about an error on their maps for around here, a few days later it was fixed...

I say let LMC know, demand they send you the right part, leave your backing plates the way GM built them, and in the process you'll probably be helping the next guy (one of us on here maybe) who needs those same cables !