The Chevy guys need to come on board here, but what looks good is a 383 with under 10/1 CR, 600 CFM Holley vacuum secondary or similar in an Edelbrock.

Take a look at Edelbrocks cam/intake manifold combos.
Dyno proven to work well together.

Considering the price of gas today, you'll probably want to opt for a mild cam, somewhere around 265 degrees advertised duration.

Try to find someone who's running a similar combination and see what they think about it as well as anything they would have done differently.

Experience counts for a lot and simply parroting things they've read in a magazine . . . I don't have to explain that....