Except I used black leather 2003 Chrysler Sebring seats. I am pleased with the results. Enough headroom, substantially increased comfort and adjustability, and I feel the looks are good (always subjective).
I'll put up a pic of the finished product here soon...just haven't taken time to photo it yet. Where in Indiana are you? I'm NW Indianapolis...you can come see what I did in person if you want...
But looking at your seat photo, without even asking for a measurement, I can tell you right now EXACTLY where your biggest problem/challenge will be...which was exactly the same I ran into with my Sebring seats:
Your seat tracks are FAR too far apart to fit in-between the rocker and the driveshaft hump of a 1st gen Bird, while allowing the seat to sit low enough to allow adequate headroom. The tracks need to be narrowed close enough together so that the OUTER EDGES of the tracks are no more than about 18.5" apart...or less would be even better/easier. I bet yours are near 22" apart from outside edge to outside edge, which will never fit...
My solution to this was a complete tear-down and reconstruction/refabrication of the seat frames. It was no small task, given the articulating power mechanisms, tilt mechanism, cushion attachment supports, structure of the seat itself, etc. It took me probably 50 to 80 hours of fabricating/cutting/welding/test-fitting? In the end, the upholstery and seat cushions remained untouched and they fit the car (and me) well. I just set the cushions aside while modifying the seat track locations, and then put the seat cushions back on at the end.
Challenge number 2: Are those out of a 4 door car? That's what CTS's are I believe. If yes, this is bad, because the front seats do not have a mechanism to easily tilt the seat backs forward far enough to allow access to the rear seats. So I decided for myself when shopping for a modern car seat that I thought would retro-fit relatively easily, that it was absolutely necessary to pull my seats from a 2-door car, in order to have rear seat access.
In a perfect world, I would have pulled them from a convertible Sebring instead of a coupe, which would have the integrated shoulder belts like yours show. But I couldn't find clean Vert seats, so mine are from a coupe...and the coupes had shoulder belt attached to B-pillar, which is bad for my convertible. So I just used my factory '68 lap belts and called it good enough.
If I were to do it again, I'd try harder to find seats from a different car. Maybe a 4th gen Camaro/Firebird, or maybe the new Camaros or Mustangs. The latest Monte Carlo was a front runner for me as well for a donor...as well as some random Mercedes I think...but I can't remember the model. those are nice coupe seats that I feel would work well. I only picked the Sebring seats because I got them for $50/pair at my local Pic-a-Part and they had cleaner leather than the Monte and Mercedes did. I really didn't know if my plan would even work or not...so I didn't want to risk newer/more expensive seats and a big financial investment for a potential failure. This was an experiment for me and I'm proud to say it worked in the end.
Here are the primary challenges with this project, with respect to screening a donor car for seats:
1. Power seat switches must be ON THE SEAT. So many cars now have power seat switches on the doors or on the center console. This would greatly complicate install because now you need to figure out where to put the switches and make them look good.
2. Coupe seats are mandatory if you want fold-forward access to rear seats...this excludes 100% of 4 door cars as donors.
3. Seat track width will need modification for most modern seats. First gen spacing at seat tracks is very narrow compared to modern cars.
4. Seat belt configuration needs to be looked at. In the end, it's often easier to just use the factory lap belt, but certainly a modern shoulder belt as shown in your pic probably would offer more safety, if it can be worked out.
