Frame question

[CURSED GEARS]

I was wondering when frame design changed if at all between 1966, to our 67-72 trucks? My 70 frame is paper thin in the back where the springs mount. Really nasty back there. Anyway, I need to put a new floor in my cab and thought this would be a good time to do something about the frame. My buddy has a 1966 LWB frame he is offering up, but I dont know if their compatable? I google it, and right off the bat it looks like the cab mounts differently.


Thanks

[seafoam68]

Anybody? I believe some parts such as trailing arms will interchange but I believe the frame itself is different.

[CURSED GEARS]

I'm pretty sure somebody knows on here. Lots of knowledge. After I typed this, I also wondered about the legality of it. I don't ever remember seeing a vin on my frame. Ive stripped the frame at least once and never saw a VIN, and Ive stripped the portion of the engine bay twice, and never seen a vin, so.......

[19Chevy67C10]

I don't know about the 60-66 frames, but I do know that the vin for my 67 frame was in the area of where the power steering box was mounted, it orginally had a manual box but was swapped out to a power box though the years...But the vin it on the top of the frame rail in the steering box area...

[CURSED GEARS]

Mine is blank there. I just thought this evening that if I have to buy a frame, why not a SWB? I know where one of them are as well.