I don't think the 40 PSI @ 9000 rpms is normal, but maybe I am wrong.
One time I rode around with a fuel pressure gauge duct taped to my dash pod for two days in attempt to catch a gremlin. i watched the gage at every possible rpm/clutch load/engine load scenario that I could come across. The gage never dropped below 49 psi. And it would onlt do it when i went from a rolling start to instant WFO, and it only did it for a second, then it would come back to 51 psi.
I think you need a new fuel pressure regulator. Your pump may be good.
I went through this bull last summer for 3 or 4 weeks, it was a tired regulator.
Ask st8e, he was there when i got towed back to the hard road one steamy-hot summer afternoon.