Frank of Advanced performance has given some good sound advice, So has Zipper and the others here.
Let me add something for you all just in case you don't already know this. Build it for higher rpm and give it a good strong lifting cam, with approiate valve springs and watch the small head build horsepower it is not supposed to be capable of once you get the revvs up. You can trick the thing into thinking or performing better than it would be under designed conditions. A good intake manifold is important.
Ever wonder how a stock class SB Chevy or (?) can revv so high and make so much horsepower with a stock engine and limited head mods?
If you do ever contemplate buying a new set of BB Chevy Conventional Heads, in my opinion there are none finer FOR THE MONEY than the ones done by our own Curtis Boggs at Race Flow DEvelopment (RFD).
www.raceflowdevelopment.com
Ed