Hi Jeremy, welcome to the site! Do you have a 55.1 or 55.2 truck? they made a change mid-year so, we'll need to know which truck you have. 55.2 is the task force era, same cab shape 55.2-59. 55.1 is earlier body style.
I have had good luck getting part #s for my cylinder kits from Napa online.
Brake shoes, you may need to have them relined.
saddle for the rear axle, assuming the spring perch? I am not sure if those are available, you may need to weld it up.
