You have to be careful. If you just stick your tool in the back side without paying attention, you'll wind up inside the galley plug and you'll get a measurement of about 3/8"...but if you then slide a small 1/4 inch socket measuring 3/8" in there it will slide right through the drilled holes. Honestly it always seemed to me that hole could have been smaller. I'll be curious as to how that goes.
