I agree. Working on a 360 would be much easier, and less custom fabrication.
I still think it's a valid thought though, since our primary interest in restoring this car is driving it... a lot!
Besides, challys came with inline 6's which, at the time were pretty lame. Modern v6's have come a long long way, not just in fuel efficiency, but in power, torque, turbo/supercharging options.