Help me build my 340

You can run everything to appear stock. Pocket and port match intake and exhaust. Back cut intake valve and get a good valve job, cut guide stems for positive guide seal.
Go with adjustable rockers. Do not over cam a street car, 230@50 for hyd, 240@50 solid. .500 lift with a true 1.5 rocker minus small block geometry loss = .485 lift. Your limiting factor for HP is going to be the exhaust manifolds, run a split duration cam to help the exhaust. If you limit yourself to 87 oct don't go over 9:1. even at 9:1 the ign and fuel will have to be spot on for 87.