Part #6 is the PAIR valve, Part #1 are the Reeds. They mount on top of the valve cover(Reeds). They allow fresh air to inject into the exhaust to lean out emmisions. The removal of the PAIR will only lighten you a couple of ounces, but will give you a little extra space under the tank. Yes, the oil pan is different also, so guess I have an extra Gen I billet oil pan!