I'm just guessing that the normal vs. heavy duty difference in a given year is aimed at the truck's use and not any mechanical differences. But I'm just guessing.
They did build splash oiling 235's before the full pressure version, but in a given year, it just might be how the truck would be used.
1948 3/4-Ton 5-Window Flatbed Chevrolet 34 Years. Now with a '61 261, 848 head, Rochester Monojet carb, SM420 4-speed, 4.10 rear, dual reservoir MC, Bendix up front, 235/85R16 tires, 12-volt w/alternator, electric wipers and a modern radio in the glove box.
