Yup. I asked Wayne Tripp awhile back about running the larger filters, which he recommends, on the R3T and he confirmed that they wouldn't fit. I'd figured as much as I'd checked the specs on the filters, measured the clearance on the back throttle body, and couldn't see how the rearmost one would clear. He confirmed that the 2780's are the only option that will fit the R3T.
I FINALLY GOT A REPLY FROM fLIP AFTER AS ECOND EMAIL, HE DOESN'T KNOW (THAT WOULD HAVE BEEN AN ACCERPTABLE REPLY), BUT HE CLAIMS THE 2780 FLOW ALL YOU NEED, SO i ORDERED A SET. F%cking caplocks, I ain't typing it a 3rd time, sorry.