The measurement on my 3D drawing is 95mm from center to center. The posts are 4mm in diameter, so you'll need at least a 4mm hole.
FWIW, I did some searching and it seems there are aftermarket loops out there. They seem to be compatible with CJ/YJ or TJ/JK.
Morris 4x4 Center - SearchMorris 4x4 Center - Results for footman loop
Lemme know the size of your YJ and I can modify it pretty easily.
Originally Posted by daddyjeep
That is cool. I want a 3-D printer. What are the dimensions from hole to hole for the footman loop on a JK? I might be interested in one if it will fit my YJ. Of course it is an easy change to make one with a different dimension.