I notice on their website (and ebay store) that Ultima has gone to all 3 piece cranks. At least on their 100ci motors and larger. Kind of interesting. Harley's been using 3 piece cranks for 20 years now so I guess they work. I've got one in my 120 and have had no trouble. Used to be that the 4" bore motors had a 5 piece and that was a plus for a lot of guys because you could rebuild them with standard components. I think the Ultima's (on all their 3pc cranks) use a proprietary crank pin of 1.620 or something like that. It never bothered me with my 120 because crank assemblies are not out of line cost wise with rebuilding one.