I believe same room in small AD truck and large, engines bolt in same, same width of frame, same length between firewall and radiator.
Steering box is different part number, but same physical size, also bolts in same as far as I know.

•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-