I show them to be the same part number from 03 to current, EXHAUST MANIFOLD 800 H.O. - 420 973 713, I asked the same questions when I did my project. I bought the 713 part and it bolts right up to the 03 to current 800 motors. The 600cc one is different tho so be sure to clarify that before you order. The center to cetner distances are different and the bolt holes all wont line up, they are really similar but wont work.modman04 said:Anyone know what the diference is between an 03 & 04 800 ho y pipe. they have diferent part # s.