I know there are some differences between the xs1 and later xs650, is there any reason a xs1 head gasket won't fit a later head, the gaskets look slightly different but the bolt holes seem to be in the same place, I found these on ebay which are the right size for a 700 kit http://cgi.ebay.co.uk/ws/eBayISAPI....4880536&ssPageName=STRK:MEWAX:IT#ht_500wt_922