The early CJ5 had a longer frame in the rear. You could tell if you ever tried to mount a CJ2 or CJ3 draw bar on an early CJ5 or vice-versa. I also saw a CJ3B body on an early CJ5 frame once. The frame stuck out past the tailgate a little so he incorporated it into a custom bumper. It turned out pretty nice and other than that I couldn't tell that it wasn't the original frame.