Is the 383 a better engine, or does the 440 just have more displacement?

383 is a LD and a "small" RB . High winding with the correct components, Cam/Springs ETC!

440 is a RB Torque Monster in Lower RPM and Lots of Juice! They Both are great! The RB engines are heavier and taller.

400 is a LD and shares much with a 383 but open to larger cubic inches in stroker versions.

A-body cars IMO should be SB as they are tad lighter and better balance! JMO!

Well unless you want to drop Late mode Hemi power in!