to get the "biggest" result use LTR450 with just PARTS & ACCESSORIES option, don't choose the ATV PARTS selections, but if you use LT_R450 you get some different parts that were not under LTR450(no space). Thats the only then the other chooses have nothing different USUALLY. Also you can find PCIII's that don't show up on parts & accessories search under LTR but are for them, its just in electronic parts or something, its in with the bikes, but Fuelmoto still have the best deal on them, and there is a FIMAK/PIM combo for 400 and some Hipers for 401...I spend to much time on ebay <_<