heyhowyadoing & Hyflyer: Yes, they make kingpin replacements, and yes they make needle bearings for our year trucks 47 to 59. Brothers Catalog.
About there reliability I dont' know, I replaced spindles only king pins and all was very good. Need any Ideas on how to replace king pins just e-mail me. It's quite a trip but fun!! popcorn The Truth is Out There (Been there did That)