Does anyone know what is different between, for example, pipes the fit a 2011 Hammer and pipes for a 2 007 Hammer (disregarding O2 ports). Is there any difference with the exhaust port fit or flange studs, or just meeting up to existing mounting brackets at the rear. I understand 180 tire bikes and 250 tire bikes, but it seems most manufactures, including Victory, separate them. But some ;manufactures will list their pipes as fitting from 2006 -2011. I currently have RPW slash 2 into 2 on my 09 Kingpin and they far out perform the Vic shotguns on the 08 Vegas. Now I replaced the RPW baffles with Big City Thunder baffles with a noticable gain, at least in mid range (make sure they are a good 6 inches in from the end of the pipe). Any help with this would be appreciated as i am trying to put different pipes on a 2007 Hammer S which currently has Vic curved pipes (whatever they call them).