ur-q WX Valve Guides

["Mike Hopton" <mike@genesis-microchip.on.ca>]

     Is it possible to replace the valve guides on WX ur-q head? I realize 
     a press is probably required to remove and install them but they're 
     not listed in my fiche as being available. (Without buying a new head 
     that is.)
     
     Are there any other engines with compatible guides?
     
     Thanks and regards, Mike