i tried a pair of monster rearsets on my 888 and they fit the boltholes but the peg was further forward than std and i tended to hit the fairing with my toes.
the very first ducati performance catalogue for the 900SS had a set of rearsets which i discovered were available through ferracci and i fit them with no problems. there is a pic of mine here,
http://www.ducatisportingclub.com/xm....php?tid=29748