@Rising what brackets did you use for your DIY roof rack?
I bought 4014 from 8020, but yours seem to be 4 bolts instead of the 6 like I have.
Anyways, I will be meeting up with @crazyfingers soon to do some measurements. I have a cheapo drill press at my house, along with a caliper to measure how much the 1/4-20 tnut sticks out from the extrusion. I will then counter sink that into the brackets that I have. But instead of using 4x 10-32 bolts like I originally planned, I will use 2x 1/4-20 like you had pictured above. Greg at GZila Designs was gracious enough to exchange out 12x 10a32 tnuts that I had ordered for 1/4-20, since they are the same price.