It sounds to me like it is not even running enough to get warm. Plus, it first has to fire on those cylinders to get the carbon hot so it will run without plug wires.
I don't think the diesel thing is happening here.
If it were it should run good when cold, sounds like it is hardly running.

•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-