Have a picture of the wheels and lug nuts?
6400 is not a usual GMC model number for 1953 is it?

You could also measure the size of the nut (and square if any) then confirm whatever socket(s) you buy match.

•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-