question about fuel rail

[quadzjr]

I looked in the 2010 GCR and I may have missed it, but I don't see anything related to the factory fuel rail. I am trying to adapt and adjsutable fuel pressure regualtor (FPR) to the car. There is no aftermarket ones that bolt on to my rail, so I was wanting to remove the stock FPR that is o-rings sealed in the bore and held in with two bolts and tap the bore hole the FPR slides into so I can screw in a fitting so I can run a standard universal one.

Is this legal?

If not how do I plumb a FPR to it?

only thing I see in the GCR is.

"An external fuel pump pressure regulator
may be installed."

In fact if you want to nit-pick I don't see where it say you can remove the stock regulator.