[PGSigns]

Looks like the spindle is 73 to 87 with the 1 1/4" thick rotors. The ball joints should be the same for 71-72 as the later spindles. The tie rods are not the same but there are ways to fix it. Here is a link from the 60 to 66 FAQ section that gives lots of information on what parts can be mixed and matched to get a rolling disc brace system. Give it a read and it will help you with understanding the ways to swap stuff in these trucks.
http://67-72chevytrucks.com/vboard/s....php?p=4450757
For what was on your truck the 73 and up spindle would have been a bolt in. Taking some time to see what have before ordering parts helps with these old trucks. Many stories about what folks find previous owners have done.
Jimmy
Jimmy