Originally Posted by Gringo
Dan are you using only center measurement? as opposed to the 18" from center. This could be the difference. My chart is old. It only goes to '73 but I've found it still works.
I have to tell you, I am going to walk out right now and see but if you go 18" from center in either direction it is probably going to lengthen that measurement because that rear body curves BIG Time. I'll go out and check, I just got home.