Maximum Performance N/A 383 build. Input wanted from engine gurus.
You have picked the worst engine out of all the big blocks to power a heavy car; the 383/400 has the highest rod/stroke ratio of ALL the BBs, 1.88.
Far better to go with a stroker crank & use 383 rods [ H beams ].
The warning below about too much duration causing slower ETs applies to 383s as well as 440s.