[PGSigns]

Here is what you have. The frame is stock 62. The rear is 63 and up to 71 if it is 6 lug. It almost looks like they modified the frame mount for the track bar. Just a bit hard to tell from the picture. You can see in the picture the modification they did to get the later rear in the truck. The trailing arms were wider at the back on the 60 to 62. Would need to see a better picture to tell how well that was done. The springs will settle a couple of inches when you get the bed back on. That will push the rear over a bit depending on the angle of the track bar. You can get it close by having a few friends stand on the frame while you take a measurement. Then adjust the track bar by half the distance you need and put it back on. Center the rod ends when you do it.
Jimmy