What is a Square Body?

[paximus]

Well I know what it is but what I mean is how do yall classify the Chevy trucks, I think the older ones were called Grumpys right, what years was that, and then the 67-72 were those square bodies or called something else, then of course the 73 to 87 are definitely what I think of when I think of a square body Chevy, so I think that is what is exactly referred to as the square body, the 73 to 87 so the question is what do we refer to the 67 to 72 as, and the ones before that are what, grumpys?


Thanks for the help guys, trying to learn here.