Thanks for the replies. To clarify my question, I was referring to early 70 compared to later 70 models, especially the Challenger. I know about most of the mentioned differences-door panel woodgrain, hood crumple zones, etc., but I had never heard of the ground location difference until I saw that description. I have a 9/11 SPD Challenger and it has the threaded nut. I have an Oct 69 parts car that also has the threaded nut. So maybe it was very early cars (Aug). The rear interior panels also have a different hole location near the quarter glass.