I have a 98 5.2L 4x4 SLT, etc etc. The only real changes to the truck are: K&N cold air intake, flowmaster 40 muffler and soon a highflow magnaflow cat. Headers are the most likely the only other mod i'll be doing down the road. Would I see any real benefits from buying a superchip, hypertech, sct etc programmer? Would it help at all using regular 87 octane? I've read some posts, reading that they can change your shifting points up to 5500rpms, but is that safe for your engine/tranny? Anyway, any insight on the questions and any additional information is appreciated

thanks guys