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.
"I never met a girl that make me feel like you do,..you're alright...Whenever I'm asked who makes my dreams real, I say that you do, you're alright..
Baby, baby, baby.. I'm bringing you a love that's true..Baby, baby, baby.. I'm bringing you a love that's true.."
Bimmerfest BBQ 2014