I have a set of 71-73 stang buckets that I have in the back of my truck, The back mount kicks up nearly vertical. Might be worked into place with a torch, but is not a bolt in. Dan ps now that I have thought of it, they wont fit without some major modification to the floor mounts.
My uncle used 71-3 buckets and mounts in his Mav. They can be arranged/modded to bolt in, but his seats do not sit centered. They are offset about an inch and a half. In other words: The bolt holes lined up, but the seats don't. Dave