Well, Harley supplied the Buell engines as OEM, per Buell's relationship with the Motor Company that said they had to use them. And Buells established a number of records with their modified OEM engines. A quick look at the records for pushrod 1650, I believe the MPS-PF set in 2004 is the same engine/chassis run in APS-PF in 2005 after the change S&S cases were dropped from M. So, a record is a record, and might not have been attained if the rule hadn't changed things. Some historians can hash it all out when we're taking dirt naps.