I know 2 words that can describe those calipers. Poo Poo. I have taken 2 sets of those mechanical calipers off and thrown them away. Wilwood used to sell them as an add on E brake to the hitech rear disc brake they sold. They are designed for go-carts. They are so poorly suited for automotive use that wilwood won't sell them anymore. That is a statement in itself. They won't hold the car on any incline,(certainly not a truck), They rattle when you are driving and if you don't get the adjustment right they will fry your rotors. They will get you past tech inspection though. Follow triaged's advice. He is wise.
my signature lines...not really directed at anyone in particular..
BE different....ACT normal.
No one is completely useless..They can always be used as a bad example