Sorry to jump in, as I do realize you looking fo a 2 wheel conversion kit but I do have something that may interest you. Its not a 2 wheel kit but it will allow you to run 8 inch wheels, with 6 3/8 inch inner. If you like it I do have it for sale.
Cheers
Ryan
Polaris Assassin
AATAC, SLP Big Air Kit, Pro Taper bar, skid plate, 136 TC rail extensions, 136 X 1.75" track and an MBRP trail can.
2004 Polaris Pro-X2 600cc
1998 GMC Sierra 4x4 5.7L
1997 Honda VTR Firestorm 1000cc
1991 Ford Thunderbird 5.0L
I don't drive one fuel efficient vehicle.