Yeah, that's what my GVW is. I believe in the USofA, the GVW for the same truck is #8800. I would think thats only a guide line. I was told my truck was used to haul 110 bushels of wheat per trip, thats about 6000 lbs. I know with the box on my truck, filled with gas, I'm only supposed to haul a ton. I have put in 4800lbs before, and the spring weren't flat. In fact, it rode like a cadillac.
I'm sure the frame on mine matches the factory specs, well, I know it does. I have a canadian shop manual and updates.
There was, I don't think, any welding done on these frames. All the spring hangers and such were riveted on. I would think that bolts would be aftermarket, or a repair. I could be wrong, as I am all the time!