I am currently running a 900ss kit in my sled with the monster twins. I am using it for drag racing and am trying to get all I can out of it. We run mostly 660' and the occasional 1000', but no more than that. I do have a wiper track with a bunch of chisels and it is sucked down pretty low. The problem I am having up here is the supreme gas is junk. Nobody runs it in there vehicles so it just sits in the tanks all summer until the sleds start running. I am not opposed to running race fuel at all. I just didn't see the sense without high compression domes. Is there anybody running high compression domes on the 900ss with the twin pipes. Also I was thinking about getting the k&n filter kit. Is there noticable gains over the stock box with 7 bullseyes in it? If anyone can help me out I would really appreciate it.