I am guessing that back in the day the 5 window deluxe cab AD's were rarer, but probably more 5 windows have survived as more likely to be restored. It is like my '64 Lemans convert, so many of them have been turned into fake GTO's, I think a stock Lemans is rarer today. I have a 5 window and of course I prefer it. I do know when I am driving other trucks I tend to find myself starring at sheet metal when I backup or change lanes. I also once read that folks in the south wanted 3 windows and small back windows on the theory that less sun heat in the cab.
