I did the body/engine/suspension off restoration.
The cab is held on by the fuel lines, 6 bolts and the wiring harness.
I started with soap and water and moved up to degreaser.
Once it was clean I moved on to a wax remover.
Then, I used 60grit discs on my angle grinder and took it down to metal and polished it up with 3M surface prep discs.

(This is a great time to cut the center crossmember out and stuff in a 5-speed.)
One more time with the wax remover and a tack cloth before hittin' it with a self-etching primer.
I don't have enough air to run HVLP, so I used RUST-STOP primer from an auto paint retailer and then topped it off with Rustoleum black hammered finish. It looks really good.
The devil is in the details and surface prep.
-DK