@keithw,
I don't know about Classic but I purchased my passenger side door from LMC and it fit perfect.
Strange though, I got my drivers side door from a wrecking yard off of a '74 Suburban, my pickup is a '74 C10 and after we got it on we noticed after awhile, we didn't notice it at first after it was painted and had new hardware and everything, and after we put the (new) door on the cab that the bottom of the door wasn't the same as my C10. The curve of the suburban cab was wider? at the bottom because the door on my truck stuck out just slightly all across the bottom, that's how we knew it wasn't a misfit. The door was identical to my old pickup door except for the bottom. I wouldn't have thought that GM would make the Suburban cab slightly wider? at the bottom.
Anyone have any ideas why? My simplistic guess is, it's a Surburban not a pickup. Do you think it would be that simple?
So if you look for a door at the wrecking yard, don't get one from a Surburban.