The kingpin diameter is the same for all early Fords from the Model A thru to 1948 (0.8125"). Can't help with the length - don't have a loose one to measure right know.
Just in case, when you put the open faces of Model A king pins together, the openings where the brake shafts fit, the shafts will be sprayed out. Model B up the shafts will be parallel to each other.
I'm a hydraulic brake kinda guy, and I don't know about the Model A k/p, but I think the '35-'36 k/p has the pins parallel when the cups are held together. The '32-'34 k/p has an approximate angle of 5* at the cup.