I will work on some measurements in the next couple of days as long as I remember it, if not just PM me. Here are a few pictures of the rack on the 65 coronet wagon parts car I have. Sorry about the 4x4 and the piece of rocker trim on it.
Matt
That is for sure a different style than the '66-'67. Pictures I have seen of '68 cars, look very similar to what came off mine. If I get the dimensions for those, it might be the same. Just not sure.