Switching out a 3rd member & the one I'm sticking in doesn't have threaded holes. It has smooth holes & a flat area to put a nut on the back side. I went to Napa & they have no idea what part number for a U-bolt kit to bolt these up. They looked thru all different years & models & just come up with the formed flat piece of metal & little bolts. Anyone know what year/model would use the u-bolt style U-joint hold downs?