Let the tubbing begin.
15 yrs ago or so I became acquainted with a woman in the Columbus, OH area. Her first husband bought her a 67 cuda FB. IIRC, he passed away. She kept the car through thick and thin, took care of the kids, and eventually remarried. After many years she finally got the car painted, running and driving, etc.
Part of that was mini tubbing. They narrowed the rear seat, had it rehupholstered, keeping it fully functional. They also sectioned a new gas tank allowing room for dual exhaust. A lot of work but it was nicely done.
Make no mistake, this was her car and she knew everything about it. I talked to her husband who had an extremely nice 1970 383-4 Barracuda Gran Coupe. He said when traveling together, her car got all the looks and attention and his was practically ignored.