1 hour ago, TomoHawk said:

The 2WD 1979 pickup had 2-piston calipers, and it looks like the 4WD pickup has 4 piston calipers.

 

You seem not to know what you even have. Instead of having everyone jumping thru hoops why not just photo

what you have. Because I have no clue what you are talking about. It keeps morphing from one thing to another.

IMO.

Photos  will take 4- 6 weeks or whenever Spring gets here.

You can turn the wheels to full-lock and get a decent view.  Stick a camera or phone under there.