A 393 or 408 with 8.5:1 compression is suitable for boost (nitrous or supercharging). Make sure the rest of the engine is setup for a power adder, otherwise you risk grenading the engine.
Anytime you use a power adder like a supercharger, tons of nitrous, or turbocharging, it's best to start with a 4-bolt main SVO block. They're designed for high horsepower environments.
You will need a forged steel crank, H-beam rods, full-floating piston pins, forged pistons, ARP studs or head bolts, and the correct type of head gasket for power adders. These usually have a copper wire to help seal the cylinder.
Just adding a TC, SC, or nitrous without due consideration to the rest of the engine components invites disaster. Money spent up front doing it correctly will be cheaper in the long run.
[ February 20, 2002: Message edited by: 2FAST4U ]