The 590 will be a BIG cam in a 383. Think 7000+ shift points. It's gonna want a very high stall converter. The 4000 stall you mentioned would be the minimum I would consider. 5000ish would probably be closer to optimum. Or a smaller cam.
You can throw all that out the window in a A body with 3.91 gears. It's a good cam. Sure, there are more modern grinds......but it was good when it was state of the art and it's still good now.
Being in a lighter car with short gears will nullify everything you stated. It will run good I bet.
