777

iTrader: (21)

i would reccomend doing what you are doing...make sure everything is tight...sounds like a lead hince "black dust"...but if it isn't get new gaskets

setxws6

My are ceramic coated and have the AIR. You must have got the race version. Did you go from stock to the Pacesetters? Because you may be just hearing a little rasp from the LTs.
Or you never know, maybe the bearings in a pulley went bad at the same time of the header install.
Or your engine maybe about to blow up???