Truck calipers are the same as 74-78 c bodies not the same as the older Cs. The calipers on my 78 (b body) Fury look like the ones on my son's 72( c body) but without having one of each in my hands I'm not sure. I dok ow they take the same pads. E bodies too. These are pin style calipers, the newer C's and the trucks are slider type calipers.
Various info:
The 69-73 calipers are technically sliding calipers, but yes, they slide on pins.
The later ones, where the caliper slides on the bracket and are held on by metal clips - those are floating calipers.
B-body calipers look similar to C-body but will not work, the B-body and F-M-J rotors are all ~1" thick, the 69-73 C-body is 1.25". The B-caliper and pads won't fit over the C-rotor.
None of the R-B rotors fit our spindles, at least 1 bearing will be different, perhaps the seal also.
Only 69-73 calipers will work on 65-73 cars when using 69-73 spindles. Unless someone can confirm the C-body floating bracket will bolt to a 69-73 disk spindle?
I have verified that the F-M-J bracket will not - but it wouldn't fit the rotor anyway.
Some of late 70s Dodge truck rotors will fit the 1973 C-spindle - that was teh reason 73 spindles were the hot ticket, 69-72 rotors were $150 each, the truck rotor was approx $50.
Must watch that the truck rotor has the correct bolt pattern - at some point trucks went to 5 on 5".
But that has changed in the past few years - 69-72 rotors came down in price.
But now reman 69-73 calipers are OOP, so we need to rebuild cores.
I have been sleuthing for 10+ years to find a combination of OEM parts that would make a nice disc retrofit under 15" wheels but no luck.
I've collected a large amount of rotor dimensions, then also handful of JY parts.
There is always at least 1 part that is a no-go. Attempted with both drum and disc spindles, too.
The factory setup has the caliper fitting tightly into a 15" room with no room for growth/error.
I've got a 17" Charger wheel for mockup, which seems to open the options immensely, but I haven't put as much effort into that.