Differences between doors

[1967Chevrolet]

I was wondering what was the difference between 67-71 doors and 72 doors

like what parts are interchangeable and which parts are different, are the doors different on the inside and do the require different parts and how to tell the differences between the doorrs

any info is appreciated, because in the parts catalogs(LMC and Classic Parts) it has different parts for the 67-71 doors and the 72 doors thanks