I'll be the "stand alone" here. Not knocking off the 440 at all, (I'm a 413 guy! ) but I'd go with the 383. It can go to 500hp, but it WOULD definitely need the better heads to start with. Other reasons for which many "may" say it's insane but:
Less rotating weight (crank mass) in the motor.
Strong rods (when NEW) proven to go OVER 6200-6500 rpms with
a good safety margin to boot.
Oversquare bore/stroke combo with a 1.89 rod ratio - great for HI-RPM HP, midrange to hi-end torque.
Easy to obtain, cheap to build, but piston prices have risen lately!
In otherwords, it's an overgrown 340!!
Only drawbacks - it NEEDS a lightweight body to run really HARD to "coin" the sub 11 sec and faster brackets. Motor needs a "pro" type oiling system for the sub-12 sec brackets, which include enlarged main oil feed and return block passages
and possibly external oil lines and filters. Helps make them live longer!! A little more work than whats needed on the 440,
but they DO HAUL THE MAIL!!