Found some in bed spare tire mounts

[fun in dirt]

I was in an old motor pool shop storage shed and found these! (I was so excited while some folks I work with thought I was crazy - LOL!)
Read up on an older thread http://67-72chevytrucks.com/vboard/s...d.php?t=712503 and have concluded that only 1 of the 4 is from a 67-72, but still a score! The cool part is, I think I have the tailgate from the same truck this tire carrier was off of (caught some guys about to throw it away 5+ years ago out of same shed, I about had a heart attack that day). I have now thoroughly searched this shed
Also found all the new carriage bolts (5/8x8") & wing nuts on the same shelf, but pretty sure they are not factory/dealer bolt just something this shop used for such.

So my question is - Any idea what trucks the other 3 are out of? They seem to be a tad bit taller & floor mounting area is made a little different. Maybe from a square body or even a Ford ... anybody know?