I think that the slp can is best,have run the mbrp and noticed that as the can "broke in " lost back pressure in turn made cool noises but in my opinion lost power. my .02 cents
I believe it was 2 inlet tubes a couple seals(donuts) from the bottom of the tubes and a coupler that connects my rocco valve to turbo.and I thought all this was replaced 100,000km ago when I dished out $15000 for a new crate motor from ford