Is there a way to tell a 31 gpm high flow bobcat from a 37 gpm? I have a 2005 S220 that came with an owners manual spec sheet showing 31 gpm for the high flow. But the historical specs on the bobcat site seem to show an increase in high flow capacity that began in 2003. There are two different specs (31 gpm and 37 gpm) for S220 that year. No later revisions to S220 are shown but the 2007 spec is for 37 gpm. I just want to get the right size hydraulic motor for my snow blower and any future high flow attachments.