Fuel regulator/ fuel pump question

[musicman]

04 Yukon xl denali

6.0l engine

Bad fuel pressure regulator

I have heard conflicting reports of the fuel pressure regulator being on the fuel rail, inline on the fire wall, and on the fuel pump assembly. Anyone change the FPR on this motor, or have the pics that show where it is. It is different than the other v8s

Thanks for any help you can send me.