Need help with caliper identification

[cerial]

Can someone help me with what kind of calipers these are. The truck is a 1984 c30 and I went to disc on the rear using the common smaller caliper. I want to replace the larger front calipers and am having trouble finding what they are or any part numbers for them.



Everything seemed to be bone stock when I got the truck down to the backing plates. Is this some kind of option? The truck does have 16.5 front rims. I have not changed anything yet with the front calipers. But the bleeders are both broken off and I will need pads soon. I would rather simply buy loaded calipers and have new breaks all around.

Thanks for any input.