Fuel pressure regulator

It is hard to say where the line is currently as they tend to fall off when the line gets old so if you cannot find it, then you can run a new one from the intake manifold. Take a look at this attachment below as you will see that it explains the regulator gets vacuum from the intake manifold.

So as long as the line is run from the manifold, then any vacuum source will work. Let us know what questions you have. Thanks