Good question for starting a range war here!
My information generally points to the fact that GMC was always a truck and coach firm that over time was driven into making light duty trucks for their fleet customers who wanted the same big truck reliability in a small truck. Conversely, Chevy was a car manufacturer that was pulled up to making trucks because their car customers liked the brand and wanted a truck with the same nameplate features as the cars.
This is really where worlds collide. Great topic to get a full-on thermonuclear war going with Chevy versus GMC guys.
If you look at literature from GMC in the days when they started making light duty trucks, it ALWAYS celebrates how the small trucks were built just like the big ones - and they were in many ways - and they even used the tag line theme "Get a REAL truck - Get a GMC!" in advertising of the 40s and 50s. Body features on light and medium duty GMCs are cosmetically identical or nearly identical to Chevy trucks in like years. But peel away the wrapper and you'll find a lot of differences in key areas. One of those areas was the power plant. GMC launched the 228 in '39 in light duty trucks. It was a full pressure insert bearing engine built to same engineering standards as their large truck engines. Many of the chassis features on small trucks before '47 were identical to big trucks. Look at the '47/'48 GMC 3 bar grille and it's is attached to the frame rails (not the radiator assembly like Chevies) exactly the same way they constructed the big trucks; for flexibilty and torsional longevity. It is my opinion that they discontinued this design in light duty in '49 because they concluded that it was overkill, but that is just my opinion.
Trucks need low end torque and power. GMC applied their truck building brains to all the trucks they built regardless of whether they were big or small.
Irrespective of where this discussion goes, it shouldn't be confrontational and it is not something that should divide our members. We are all children of our inline heritage. To find a common enemy, well, that's why God gave us the V8!
Just some brain droppings and take them for what they are worth.
