Ed, thank you for your reply. I have read a number of your comments on other threads and have learned a lot. In this case, I am still wondering. If the engine has performance cams with overlap and a lower back pressure exhaust system, those improvements would increase the volume of air the engine can take in and expel out, no? More air would flow through this modified engine that would flow through a stock engine, no? I am just wondering if the stock L Jet air intake system (throttle body, black tube across the engine, etc) would be restrictive. I have read somewhere else that the L Jet air intake system was actually designed to be somewhat restrictive over 4000 RPM for the stock L Jet to meet US emissions requirements. Thus my question, if the air flow isn't there for more fuel, how to larger injectors help and how do you get a power/performance increase? Thank you.