I have already given it the thought that it would possibly be cheaper to rebuild the factory motor, put in a good cam, and hone or bore out the hi-po manifolds and factory intake to allow for better air flow. Will also port and polish the heads (2.08int., 1.74exh.). Does anyone know if this is the '906' head and if they are good heads?

I want to build this motor up and run real nicely but still have the ability to put a ricer in its place on a rare occasion. Anyone have suggestions for getting a HP 383 to make 400+hp using the "stock" appearing parts such as the intake?