Use the perch bolt or a 5/8 bolt to assemble the bosses on the axle.

Put a thin piece of card (cereal box is a good thickness) between the axle and one boss.

Nest the c-plate against the bosses and slide the plate along the boss. It will probably slide about ¼” total. Split this amount and tack the c-plate to the bosses.

Remove the assembly from the axle and finish welding the bosses to the c-plate. Repeat with the other c-plate.

Assemble the side plates using the urethane bushing inner sleeves. Don't use the urethane bushings! Add the thickness of the cereal box cardboard for clearance.

If you have the kit with the bolt-on Panhard hole in one side plate, assemble that side first. The bolt-on plate goes on the passenger side bracket, closest to the frame.

Hold the side plate assembly against the c-plate assembly and tack. Leave the spacers between the side plates to give the assembly more structural integrity while welding.