Back up sensor hole diameter?

[NewsShooter]

I've searched and searched and haven't found a post that notes the size of the back up sensor hole for the factory steel bumper. I bought an Ironman 4x4 bumper, it has holes for the sensors but they aren't the right size to mount the sensors. Just trying to figure out the size I need to enlarge them to fit the sensor mounts.

Sponsored

 

[NewsShooter]

So I was able to pick up some of the mounts needed for the sensors on the OEM bumper today, the rest are on order. It appears that the hole should be just over one inch in diameter. The holes on the Ironman 4x4 bumper are 0.89, looks like a reamer is in my future.