67-73 Abody frame Rail and Rad Support

I thought the front frame rails were the same except for 1967, they spaced them further apart?
When Hoosier Garage, youtube, repaired front rails on his Duster he said somewhere early '70s upper control arm mounts got a reinforcement. But I think geometry is same. Front bumper mounts prob diff on later cars but cutting welding can get around that problem. Overall I think they interchange '67-'76