these web sites help me alot should be what you need to know http://www.mortec.com/bbc.htm

and if you want to make big power

 most bang for the buck http://www.procharger.com/marine.shtml

heres the breakdown http://www.procharger.com/M_engine.shtml 

 also http://www.keitheickert.com/products/Superchargers/procharger-carbureted-kits.htm