Yes they are but not by much at all. Frame wise There is nothing different That i everseen or found out. I have owned them all from 62-70 Two of them being SS,One being a four door No wagon as of YET lol Both my 64 & 69 were SS cars my 69 being a BB 396 bored to a 427 10sec car many year back But also a 4speed. My 64 SS was stock L6 power glide on the floor.