Let's play another episode of NAME THESE PARTS

Along with the '73-6 upper control arms, you'll need calipers and matching caliper brackets/hardware/pads, rotors that will take the correct bearings for the spindles (fairly hard to find the last time I checked), grease caps, nuts, washers, etc. for the bearings, and brake hoses for whichever caliper mounting (front or rear) you plan on using.