What kind of horsepower can be expected/and or proved from bolt-on mods + valvetrain upgrades? And I mean all of them done right...headers, exhaust, intake, pulleys, cam/lifters/springs, and a dyno tune. Or is it more logical/economical to just write a check to STS? I need to develop a good plan before beginning to buy. I dont want to buy a intake and exhaust just to rip it right back off in six months for a turbo install.