On mine I drilled 2 pieces of 1/2" plate in a press so they are all paired up and tapped one plate per pair. That way I have 8 grade 8 1/2" bolts holding my junk up. To use a stock crossmember just use square u-bolts over the frame down through the holes in the crossmember. Easy as pie, Marlin's truck is set up like that.
