Gotcha, thanks for the pic. You aren't using OPs rack, that's what confused me. I like your design, clean and simple. I wound up ordering the same rack as the OP, https://www.amazon.com/gp/product/B00FQT1FF4/
I plan to use these same mounts, but it's hard to see how you attached the cross-member to the mounts, can you share a closeup pic? Also, what did you use for the cross-member?
I was thinking about using u-bolts and the steel conduit as the OP mentioned, but open to other ideas of course.