This listing is for a NEW OEM snowmobile rear suspension pivot block. The part number on this part is 580664300.
Looked the part number up online and found that this will fit the following machines, may fit others too
Formula 500 Deluxe, 1998
Formula 500 Deluxe, 1998;
Formula 500, 1998
Formula 500, 1998;
Formula 583 Deluxe, 1998
Formula 583 Deluxe, 1998;
Formula Z 583, 1998
Formula Z 583, 1998