Is there a way to correct the speedometer when larger size tires are installed. The engine and 3 speed transmission are stock. The reading is well under the actual traveling speed. The truck has been restored.Thanks for your help.

Yes, there are methods. Usually, speedometer cable driven thimble gears can be exchanged for different driven gear sizes and result in a speedometer indication that is relatively close. However, thimble gears for your transmission are likely no longer available. I had a 1950 3100, 235, "three-on-the-tree" non-synchro trans, probably just like your's.

Another method is an inine gear unit which allows ratio changes. There are several places offering such units. Perform a Google search for "speedometer ratio adapter" and you'll find hundreds.

Thanks ,I will try that. I was aware of the transmisssion gear but finding one with the correct ratio seemed impossible.