Well since I have spent so much time dealing with trying to find out the nterchangeability of these d**n e-body seats I figured I would share what I have learned... I had (2) complete 70 SE seats, (1) complete 71 seat, (2) complete seats, (1) 73 seat bottom, and (1) 70 seat back at my disposal to learn from. First and foremost, when I am referring to interchageability, I am talking about the SEAT FRAME, not the buns, skins, or wire inlays. Every year has a different skin pattern, so no year is entirely the same from another, but the frames may be and the rest can be adapted. Also, when I refer to "seat bottom", I am talking about the part of the seat frame where you sit on, when I say "seat back", I am talking about the part of the seat frame where your back is against, not the actual back of the seat.
Starting with seat bottoms, 70-72 seat bottom share the same 6 rows of springs and are interchangable, except the stops are in a slightly different location but can easily be moved. 73-74 seats have 4 rows of springs and are interchangeable with each other, but not with the 70-72!. Moving on to the seat backs, 70-71 share the same spring pattern, which is springs attached to the frame and are somewhat interchangeable with each other, the difference being the latch assembly, the 70 does not have the little cage that the 71 seat button sits in, however if you have 71 seats, you can get them recovered using the 71 latch assembly without problems. 72-74 do not have the springs in the seat back frame and the seat foam is extra sturdy and acts as a giant spring, these seat backs are interchangeable with each other and share the same latch assembly, but are not interchangeable with 70-71. Moving on to seat tracks, 70-72 have the same seat track, different nobs, but physically the same. 73-74 seat tracks may be interchangeable, but I saw a set on ebay and they do not look like the 70-72 style, so beware. BTW, the seat backs are left and right side oriented, they cannot just be moved from the passenger to the drivers side, they DO NOT have the provisions for the latch assembly on both sides!!!! the seat bottoms can be moved around as they have the provisions for both driver and passenger latch hooks and stops. Now there may be come exceptions to the rules I laid down, but for the most part, this is how it is.
With all that being said, heres why I needed to learn this. My old man bought a 70 challenger with incorrect year e-body seats, he than bought new skins and buns and when I pulled the seats out to get them reupholstered I discovered they were the wrong seats. The passenger seat was a 71 e-body passenger seat and the drivers seat was a 70 PASSENGER back mated to a 73 seat bottom....it was a mess. Since he bought the skins and buns, he was stuck with them so I had to find a way to make it work. Thanks to 4C, I had a pair of 72 seats to work with and the fun began. Heres how I did it......I took the 71 passenger seat and left it as is because, for the most part, it is the same as the 70. So now needing drivers seat, I took the drivers seat bottom off the 72 and the 70 passenger seat back and put them together. Sounds good??? but, now I had a drivers seat with the latch assembly on the wrong side, so this is where stuff turned from easy to hard. I had to take the 72 drivers seat back, cut out the latch assembly mounting brace, then cut out the mounting brace on the 70 passenger, weld the 72 brace in the 70 seat, and finally add the cage that the 71-up bottoms have. In the end, I still didnt have 70 seats because I didnt have the latch assemblies, but 71 seats are very similiar and will work. Basically, it really isnt worth the effort of piecing the seats together because it is TOO much work. If you need 70 seats, than try to get 70 seats, if all else fails, get 71 seats because they will work. Good Luck.....
