Best resource for rebuilding Carter carburators?

There is a book by IIRC, SA Design in "How to Rebuild your Carter Carb" which also includes Edelbrock carbs. Inside gives step by sep instructions with pictures and exploded views of all 4 Carter carbs. Very easy to rebuild, tune and modify.

Your 383 generally came with a 630 cfm AVS or 600 AFB depending on the year. There are OE 750 versions of the AVS that will work fine. I like the AVS over the AFB because of the spring loaded air door that really helps prevent bogs that the weighted air door of the AFB tends to hand out. Edelbrock does not have a 750 AVS, only a AFB 750. They do have a 800 AVS.