The 83 has 2 pistons, one is smaller than the other. The ones from the V6 trucks had 2 large pistons. The ones on the 4cyl IFS trucks use the same size piston, but have a wider gap to accomodate a vented rotor.
Bob
ok, now somebody tell me what calipers i have, my front axle was actually assembled in 78, according to the bell castings, and my front calipers have 4 pistons, my pads are like 2"x5" with 2 holes for the little pins to hold them in place, i say this because in the past when i go to but new pads i always get these smaller pads with one pin hole
