R30 front brakes

[staverironbrand]

I just picked up an 87 R30 dual rear wheel flat bed this week. It's pulling to the right when applying the brakes. I am thinking of replacing all the components, (calipers, pads, etc.) and the the soft lines. The master cylinder was recently replaced. In researching new calipers I've run across two different brakes sizes a 13x3.5 and a 13x2.5 inches. How do I tell which I have? I've owned half ton square bodies, this is my first 1 ton and I know they are a completely different animal. Thanks in advance.

 

[nvrenuf]

Duallies have the bigger 3.5” wide rear brake shoes.

 

[staverironbrand]

So it's referring to the rear brakes and not the front? I can pick up calipers and not worry about the size at the front?