Thanks guys, I have looked on ebay.. haven't found them yet. But I did email the listing that KC posted up!

Just need to figure out if it is the right set, He believes that they should rebuild a 31-51 big truck axle.

Does anyone know if this would be true? My gut tells me that there were probably different king pin configurations.

Does anyone have the manual for a 36 or could at least tell me what the proper Part number/ size would be for the king pins?