Swapping 13"x2.5" to 13"x3.5" drum brakes

[Supercharged111]

My '97 K2500 7.4L (8600 GVW) has JD7 brakes.

I'll have those rear brakes apart as soon as I get the intake gaskets installed on the K1500. Again.

In '97, at least, there's JB8 single-rear-wheel, and JB8 dual-rear-wheel. The difference is in the front rotors--same diameter, but about 1/4" thicker on the DRW. That may mean that the calipers are also wider to accommodate the thicker rotors.

Didn't the dually calipers have a bigger piston anyway?

 

[Schurkey]

Didn't the dually calipers have a bigger piston anyway?

I don't have that info. A dive into an on-line parts catalog--NAPA, or O'Reillys, or whatever, could tell you if they're the same part number or different. No promises on the description including the piston diameter.