rene4406 look at the link I posted in my reply earlier and does200’s link to Aeromotive faq’s. These regulators are not designed to hold pressure with key off.
Ok i hadn't read it all
But this plug does not have a satisfactory appearance and we do not test the injectors by listening to them, even with a stethoscope, we dismantle the rail, we feed the pump and we check that none is leaking and then we make them charge all at the same time in identical and transparent containers and we check if they have all delivered the same quantity.
Check the compression is also a good thing.