Hy mechanic58, my jobber parts books show the rear wheel cylinders as United part number 3677, that crosses to Napa p/n UP3677 reserve online price $52.49, the Raybestos p/n at RockAuto is WC3677 $61.79, hope that helps.
I really appreciate this tip. I ended up buying a set from Rock Auto. I am still shocked that they had these in stock. They even have the best price of anyone else, by far. I buy stuff from Rock Auto all the time. They even sell seat upholstery for these trucks far cheaper than you can buy it anywhere else that I have found. That shocks me too.
