I think I found my missing Xmember... It was right there in front my the whole time, just not in it's original place
I am almost certain the original owner cut the cross member and moved it back just behind the last body mount and has it running above the frame rail and welded it to the square looking block.
He also fabricated this piece that is welded to the backside of the xmember so he could have a hitch, which he cut the hitch off, btw.
Is this square looking block that is sitting on top of the body mount stock on these blazers or is this another brilliant modifications the OO made? I'll look again today to see if it is welded to the body of the blazer or the top of the frame.. If it's welded to the top of the frame then I think it's definitely a modification because other blazer frames that I've seen with the body off the frame have not shown this piece.