A 14 bolt axle from a dual wheel cab and chassis (without a pickup truck bed) has approximate 63.5" Wheel Mounting Surface to WMS measurement, and it's 8 lug.

https://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=686189&page=1

Grigg

•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
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-