Why are they different part #s?
Not sure, Look at Ice Age's website. They state this as well. They may have more info.
Matryx KHAOS Rail Kit
Replacement slide rails for your 2022-2024 Polaris Matryx KHAOS 850, 9R, and 850 Patriot BOOST snowmobile suspension. 2024 RMK AND KHAOS MODELS OF ALL TRACKS - YOU WILL NEED TO RUN OUR MATRYX-STYLE ANTI-STAB KIT AND 2x MATRYX RAIL TIPS FOR INSTALL TO REPLACE THE OE TIPLESS SETUP All Matryx RMK...
iceageperformance.com