Just to clarify, we got this SB2.2 from Bill H used. He had built it for Mo Gordy in NC. I think that Mo requested the LS-1 firing order cam and Bill built it that way...The reason I just think it idles smooth, is that I know the HP this engine makes, I know approx the duration/lift this cam has and when I compare it to other rollers that we have had in the past it just seems to idle smoother and doesn't have that characteristic hard rump/rump...LOL No idea why, just figured that maybe the 18726543 firing order had something to do with it...Any other ideas TB or Perfconn? I was never sold on the 4/7 swap...how about the 4 cylinder swap? why would Chevy do it? Thanks for any replies..