Ok I'm going to fix the exhaust on my car. I am going to replace the resonator forward leaving the factory pipe back and factory mufflers on. What size pipe and what resonator should I use? I was either going to use the mustang headers or the factor manifold, but haven't decided yet. Motor mods are 70mm TB, 73 mm mass air Kn filter 10% early blower pully with intake and blower port matching, slight port job on blower.