The 1.5 goes into the frame to where the bolt is. A piece of 2x.250 strap goes across the top of the frame to the same bolt hol

The 1.5 goes into the frame to where the bolt is. A piece of 2x.250 strap goes across the top of the frame to the same bolt hole. A 3/4" OD sleeve drops down from the top and into the 1.5 at the bottom so the bolt can be tightened without crushing the frame.