Who was it that documented 300 CFM out of an rhs head? Not 290's, but 300.
Iirr the rhs ootb from RHS was a hair behind on low mid lift compared to the ootb eq. The rhs had better peak ootb.
Other people did their own versions with their valve job and valves and those are the ones that do the 260-270 numbers.
May have been @IQ52 . I think I remember him posting once that their experience on the Magnum style replacement heads showed the INDY/RHS deal was slightly better than they saw from the good EQ heads.
I hope I am not mis-quoting him. Nothing but respect for him.