l have a 6.0 v12 2004 bmw 760 li...i know it is already fast but l would love to add more hp...what is the best way to add extra hp excluding turbo or supercharger since those are obvious

Turbos and Superchargers are the only big HP adders that do not require serious engine overhauls (and depending on how many psi you run them at, they might require that too). Go to bavauto.com and surf through their performance modifications. l think they offer performance chips, more aggressive cams, and things of that nature.