I've been lurking on this site for many years, recently decided to stick my head up out of the shadows.
I have a 67 Camaro that Dad and I bought 30 years ago to turn into a race car. It is a low/no option base model that we removed the entre floor and built a 2x3 frame that runs from the stock sub frame to the rear bumper. We originally set it up with ladder bars, coil-overs, and a 12 point cage. Unfortunately we never finished the car, Its been sitting outside in the weather for almost 30 years.
I decided that was long enough to wait and started re-vamping it. So far I've removed the ladder bars and replaced them with a triangulated 4 link, In the process of prepping for a new floor. My plan is to use a stock floor notched for the frame rails to pass through. Replace the 12 point cage with a 6 point (more street friendly setup). It will have 29x15x15 or 29x18x15. haven't decided yet, I have plenty of room for either. I am planning on having a rear seat of sort as I have young-uns.
I really need to see some pictures of Wide wheel tubs (not mini tubs) in cars that retained the rear seats. Need inspiration on how to tackle it.