73 parts same as 72?

[kidatheart]

I have a 72 k10 frame that has been sitting for 20 years and is missing parts, that I am supposed to be buying. I just bought a complete 73 GMC k1500 that runs and drives. Does anyone know how much of the running gear will interchange with the 72? Is the 73 205 transfer case the same as the 72 would have had from the factory, or were changes made? Are the spring hangers the same width on the differentials? Are the drive shafts the same length? Are the springs the same length? Is the transfer case shifter the same for the two years? So many questions.... Any info is a great help. Thanks.