I have a 121 to 144 kit on mine and will probably go longer this summer. I am thinking a 156. I would like to buy a set of rails but can't find one in the polaris parts catalogue. There is a guy on snowest who makes them for pro-x. Will these be the same as for the pro-xr? The polaris parts catalogue shows the pro-xr rails as being different. I assume they may be just meatier but would all the parts line up if I did a swap?

would a set of 156 rails from a rmk work?

Also, does anyone know who makes a 121 to 151 tunnel extension? The tracks usa 121 to 144 may be a little short.

I would just go with a 159", not any longer than a 156", but there's more tracks to choose from. Plus it's a more common length. Polaris doesn't make 159" rails for a Pro-X and I don't think RMK rails would work. I'd get some rails made by the guy on SnoWest. I can't remember his name, probably the same guy you're talking about. Tracks USA 144" tunnel extension WILL definitly be too short. I'm not sure who makes one, you may have to have Van Amburg or someone similar that does custom work to make one for you.

pro x (all) and xr(800) rails are the same.....2003 ~2004 are basicly the same.

xc-mark, how about 440 pro-xr? Is that a different rail?

They are basicly the same rails.. nothing that i know of differs between the...