Like has been said, Paxton makes a complete kit. Also, you could run low boost on the 273 and then while you enjoy it you could be building up a different engine (over time, no rush because you would already have a fun supercharged small block) that could take more boost and make more power. Then when it's built and ready to go, just pull out the 273 and drop in a different, larger small block, put the supercharger on it and crank up the boost.