Starting in late 03/04 on Mustangs ford got rid of the scrader valve to save money, 05 continues this trend. If you want to add a fuel pressure guage or wet nitrous
kit there is no easy way to tap in for fuel (cutting the feed line is an option but something I would try to avoid).
For 05+ I had this piece made:
It installs between the Rail Pressure Sensor and fuel rail, it has two 1/8" NPT ports on it.
I am going to make a part for 03-04s as well, I would probably use it even if I did have a scrader valve. The schrader valve is 1/16" and tends to break easily if overtorqued.