If I was a betting man it would be a tough call. You would think they would be very close. I seem to recall the 69 rear end was mounted higher in the frame to get the car lower. I would do a lot of measuring to see how feasible it is. If the body mounts are even a couple inches difference that could cause major headaches and require too much fabrication to be worth it. Let us know if it works though. I have a 70 that needs a frame.