Assuming your OE regulator is on your rail youll need to remote fit your PBV.
Set your baseline pressure at idle with a fuel pressure meter, borrow one from a garage or something......just like a tyre pressure gauge.
The benefits of teh PBV are really small on a NA engine, its just better at reacting to manifold absolute pressure with its 2 or 3 times larger diaphram.......which most people feel as better response.
wont make much if any diff.