I just re-read your article and see that they did come w/ 19.5's. That makes me wonder if the Isuzu with 22.5's would be a good choice.

51 Chevy 2-Ton Flatbed, 6bt Cummins Non-Intercooled Diesel, Old Smokey Power Pin, Airdog Fuel Prep/Pump, Non-Overdrive (727) Transmission w/ Gear Vendor (6 spd w/ overdrive), 4 wheel disc brakes, 4 wheel airbags over leaf suspension, Power Steering.

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49 GMC Tractor w/ Sleeper ready for restoration.