I have metallic berk hfc w/ stock exhaust and i love it i was actually thinking of leaving it like that too. sounds great. worse gas mileage tho cuz i'm always running around at higher rpm now. not a huge difference power wise but it is a little bit better. I have a revup with 5/16 spacer and homemade mrev, k&n drop-in and titek air duct. it sounds nice and deep but there is a little rasp up top and rattles on the way down a bit.

overall i likes

 

post up a vid!!!!! cause all I have heard is Berk's own dyno video, I want to hear other clips.