Forced induction cost big money unless you can scrounge up all used parts and fabricate everything yourself. Even so, a turbo would probably be cheaper. Slants have been running for years now using junk yard turbo setups put together by their owners.
Theres a discussion on supercharging the Mopar 6 going on now on another board. A company will soon offer a supercharger kit for around $3400. You supply the 4 bbl carb modified for blow thru($450), the fuel injection fuel pump and boost bypass regulator($305), and recommended water injection($740). Your motor should already be up to the task for the increased power or add some pocket change to the above figures.
Heres the mock up of the system:
