Buy a double #35 sprocket and get a shop to wire edm the bore. Not sure you're going to have much luck finding that. Sure double #35 is going to be strong enough?
I dont have the 440 I bought a 87 skidoo strotos 503 fc cut the front off going too weld that to my frame looking for a sprocket to fit the shaft coming out of chaincase that drives the track its a hex shaft