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

My post is relevant with respect to the engone with more torque and less valve shrouding via a larger bore size making more power. Being a forum of discussion we may tend to stray from answering the OP's question 66 posts into the thread.

Having driven and tuned the 383 in my GTS, most recenty, I have a fair amount of direct experience in the matter.

The 383 is no punk and they are Legendary as we all know. 400's make great fake 383's : D

As with all projects, do what you can, with what you have where you are at. Any rebuilt big block is a good time IMO.