Bro I dont know, but dont ya hate that. Dont do to much grinding and cutting to make them fit. the DS conversion was way to much cutting and grinding for me. I think the MX and IRS version run the same front end minus the remote cans on the front of the 450.
Mate, take your time with the shock mods, see if ya can get them miled down profesionaly to make them look nice and pro. You should be able to get upgraded springs and valving from Fox if there a bit soft.