Big mistake doing it off the frame. I do this type of work for a living and am warning you it is not a good idea.
Ok maybe im missing something? Its a 67 chevelle full frame. Every video I have seen they do it frame off with body braced. I saw one guy do it with frame on and it looked like a train wreck trying to get that one piece in from top. I will take your advice and think? I appreciate it!