I expect there's info out there just not to be found under the "proper" model number. Do you know any other distinguishing features or nicknames for those guys that might help in your searches? Can you find anything in the service and parts manuals for the trucks they were installed in?

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
---All pictures---
"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-