Hey GM A Body fans!
I found this article on frame interchangeability from an interesting blog called phscollectorcarworld. I thought you’d find it useful.
The blog article makes reference to a book called 1969 Hollander Interchange Manual for domestic cars and trucks, which as the title explains helps us find parts that cross over among similar models.
Here’s the link to the article:
Here’s a link to the book, available on Amazon:
Here’s another link to similar book that I found on Ebay: