Would probaly be more helpful if you gave us the complete id numer (you can x out the last 3 digits). Don't forget Ducati made a 400ss, what was basically a sleeved down 600ss motor.... you might want to avoid that one. All the weight and none of the power...I found an engine with Lc4x00..... And am trying to ID it. My searches net me the fact that the owners manual points out the fact that the first 3 designate engine model, but dont list them. 900ss?
I am pretty sure it should be ZDM 400 A2 00000 for a 2v 400 ... first 3 are for ducati next three are the displacment A is for aircooled and 2 is for 2valves.Lc4x002899. I didn't put them up because I thought they were just sequential serials numbers and ,err,..... I forgot the rest!