14 ff drums

[Slow build jim]

I have a 79 3/4 14 bolt that I am swapping to 85 1/2 ton. I am going from 11 " to 13" . I found backing plates and cables .I am lost to what size drums I need ? 5.20 or 6.5 I using 13x 2 1/2 shoes . Is it an option for in bound and out bound drums? Thanks

 

[dvdswan]

I could be wrong, but I think one is for single wheel and the other is for dual wheel.

 

[nvrenuf]

11” vs 13” on an srw axle is the difference between gvw options.

All drw axles are 13” bu those are D70HD’s unless the truck was a cab & chassis.