Have a set of center seat belts for the middle 3rd seat, had to drill out the plastic phillips head screws that were installed by the factory in the threaded anchor holes. They look smaller than the standard holes for the driver and passenger belts does anyone know what size bolts these take?

All seat belts in the US use a 7/16-20 thread. Or at lease most of them...

Pretty sure they are the same as the normal seat belts ...

Ok that is what I thought, I am going to tackle it again today, maybe didn't get all the plastic screw remnants out. I'll use a heat gun on it.

Yep plastic sleeve was still stuck to the threads heat gun took care of that, same size bolt works. Thanks!