There should be a gap at the rear of the clamp. Take the top half and place on a flat surface (like glass) one end may be shorter than the other. That one goes to the rear. Alternately, the top triple may be ground to achieve this same objective. With bars off, lay a straight edge across the flats. You may find the forward flat in a higher plane than the rear. Align the cap with the lower so the natural gap is toward the rear. Tighten the forward bolt first, the the rear.
Cheers,