Hard top questions rear side bolt size

[Thealien]

The brackets in the rear that hold the top to very rear by the tailgate. What is the thread size of the bolts that are supposed to be there. I cant tell by looking and I need to chase the threads with a thread restorer as other than the front there is nothing holding the top on.

My Blazer originally had a single wall top. I went to take a bolt out so I could install longer bolts and hold the top off the body so the body guy could adjust the windshield frame to door gaps without the top affecting those gaps. When I looked under the bed rail there are the captive nuts for a single wall and absolutely nothing but the front bolts holding it on.