on a stock single cam i would only suggest around 5 psi or so and you should definately upgrade your fuel if you plan on boosting higher in the future.... right now to only boost about 5-6psi on your stock motor you shouldnt need fuel upgrades except for maybe a pressure regulator or somethin along those lines... stock pump and injectors will do the trick... if you want to do it right though, i suggest saving your money and either get a swap or start building the single cam motor... give me some more info on what your goals are and what modifications you currently have as well as those you plan on making, and i will try to help you out to the best of my knowledge....