They may not have done it back then....
So why do Semi trucks with even stiffer springs have shocks now?
A railroad car will even have shocks, and they are really heavy.
I still think that rear shocks will help on my truck, I'll let you know if they don't.
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-