Ok... So if I drill out the holder to accept a 3/8" bolt.... Its 13/32 wide. Says it is sealed even though the picture doesn't allude to such...
https://www.amazon.com/Kilian-D-2269-Outside-Diameter-Bearing/dp/B003XU6QTS
https://www.amazon.com/Kilian-D-2269-Outside-Diameter-Bearing/dp/B003XU6QTS