Stop in for a cup of coffee

383 and the factory rating isn't bad on the HP count, but there is plenty room for improvement. I've had good experiences with Crower Cams in the past and they have a nice selection of grinds.
The old Edelbrock DP4B intakes work good. They still make the steel shim head gaskets. MOPAR Edelbrock DP4B 383 Intake Manifold Four BBL Aluminum Big Block 400 70 71 | eBay