I installed the -6an female swivel to -6an male adapter and installed the fuel pressure gauge on the adapter. This adapter does not leak.
With the pressure gauge installed and its now safe, I can see what the fuel pressure is with the current stock fuel pump. At idle, pressure is about 3.5 to 5 psi.
adapter is -6an male to -6an female swivel with a 1/8 npt port for a fuel gauge.