Frame thickness on 1/2 Ton vs. 3/4 Ton?

[kilomanjaro]

I just got a 1/2 ton 4x4 from randy, I got to looking at the frame and it is the same thickness as my buddies 3/4 ton 4x4(as well as all other 3/4 tons I have seen). I know that it is thicker than 1/2 ton pickups, blazers, and suburbans, are 1/2 ton 4x4 pickups thicker than other 1/2 tons. Also the rear driveshaft is about 4" in diameter like a 3/4 ton 4x4, is that normal for a 1/2 ton 4x4? I haven't checked the VIN on the frame to see if it matches the title and VIN plate. Anyhow just looking for someone's input here, I am kind of stumped, other than the possiblity of someone swapping a 3/4 ton 4x4 frame under a 1/2 ton 4x4 pickup I have no answer---thanks
john