Karl's right...to add a supercharger would probably require considerable work to the engine. You'd most likely need to lower your engine's compression ratio to avoid detonation.
There are two types...one sits on top of the engine where the intake manifold would go, the other looks like an overgrown alternator (it's called a centrifugal supercharger) and will take up a bit of real estate to the side of your water pump. The 289 models were sometimes fitted with a single centrifugal supercharger...and IIRC TWO centrifugal superchargers were used to make the SuperSnake models.
How much extra air/fuel mixture is forced into the engine is adjustable...pulley ratios and all that sort of stuff. It would probably be possible to add a centrifugal one to an existing engine if you "gear" it properly. Again, it all depends on how high your compression ratio is.
Good luck!
Cheers!
Dugly
