I've seen some with engine behind cab.
Don't see a lot of COEs to start with, so not seeing the exact conversion you want already done doesn't mean it can't be done or you can't make it work. I couldn't find mention of a single 53 series Detroit swapped onto an AD before starting on mine. Now several have come from behind and beat me to the finish line..

•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-