is a SCPerformance cat-back exhaust with magnaflow resonator and two high flow mufflers that measures 2 1/2 to 3 to 2 1/2 inch pipes and a k&n panel good enough for a 5% overdrive pulley on the blower? or do i need headers and new down pipes too? how much will a 5 % overdrive increase torque and power? i dont wat to run a 10% just yet, mabey later, all i want is a low-mid 14.