Since you uncorked the headers, whatever exhaust you get will be quite loud especially if it replaces the 2nd resonator closest to the muffler.
I wouldnt expect too much or if any gains in power, but it sure is going to sound great.
"Driftin' away like a feather in air. Letting my soul take me away from the hurt and despair.
keepin' it vertical, forever elevator. Riding that escalator to something that's far greater.."