I did the same with a '54 Chevy car. Ended up cutting the A pillars, body mounts, and the floor off half way to the seat. It was easier to load and haul that way. Spent a ton of time cutting it close to the dash and then sold the dang thing for $100 to a guy who wanted to fix where the radio had been yanked out.
I'm getting one of said $500 restorable cabs from TX as we speak...easier that way. Michigan makes them perforated.