[crazy longhorn]

If your crossmember is in good shape(no cracks or rot), you dont need to replace it. On the 3/4 tons, they use the same balljoints/tietods fro 71 to about 86. They also retained the steel a arm bushings that the 1/2 tons gave up in 73. to bolt the spindles on, you need the upper & lower balljoint assys, tie rods(innners,outers, & sleeves). the center link is also a pc I would grab. As a rule, 71 on should go on the center link. Your steer stops will be different on the lower a arms, so you can grind the stops on the spindles, or use the later bottom arms. You will find the lines & hoses routed differently on the later truck.....you can adapt the later setup with a little work(my 69 has 75 brake pcs)......lines prop valve, master & all. Another option would be to set up like the 71-72s on the brakes(no doubt an easier route), & just weld the tabs for the hoses where needed. You will need to change the master, & prop valve for the disc brakes. Good luck,crazyL