This is because the 1976 and older spindle uses a smaller inner bearing
GM 1 ton drag link end with 7/8"-18 right hand threads
GM small bearing spindle
you'll notice that the locating tab for the spindle is offset from the holes
Taper: Chevy drag link (larger than tie rod)
Four Link 1-1/4", Chromoly Heim Joint, Kit, 2-5/8", 3/4" Bolt, 1-1/2" ID Tube, (PM5121-1125-34) DAN706527X-HD This is because the 1976You selected the 3 4" hole four link kit!!! 1 1 4" Chromoly heim joint kit (dimensions below). This kit includes everything to rebuild a 4 link suspension: 8 heim joints (4 L H, 4 R H), 16 stainless steel misalignment spacers (3 4" X 2 5 8" wide), 8 jam nuts (4 L H, 4 R H), and 8 tube inserts (4 L H, 4 R H). Use the drop down menu to select the size for the misalignment spacers. The black oxide coating on the tube insert IS weldable. It does not need