Carburettors maximum fuel pressure the needle and seat can handle is no more that 6 lbs, ideally at idle 3 to 4 lbs is where I would like to see it. However to feed a performance engine we need fuel volume and at wide open throttle or any off idle driving then the fuel system needs to be able to supply consitent volume to the carby.
   
Setting up the fuel system with the engine running on the dyno is not for the faint hearted, in fact it feels dangerous, probably because it is.  Just setting the fuel pressure at idle does not show you what will happen when the engine is loaded and at some rpm. All the race fuel pump instructions say set the pressures with the engine at WOT and loaded ..... yeah good luck with that.
   
So I have come up with a carburretor similator that I can simulate the fuel system right up to and including the needle and seats of a Holley style carbie.  The fuel pump runs and the pressure regulator can be set for idle and wide open throttle, yet the engine is silent, because it is not running. I can here the whole system working and casually set and test.  The test rig I made sits on top of any 5 1/8" Holley 4150 neck, so there is no need to remove anything from the engine.
   
The fuel line gets redirected to the test rig and the test rig jet taps feed off into a jerry can, or approved fuel container.  I can also opt to run methanol needle and seats [they flow more] to test a methanol feed carby.  The fuel lines on the test rig are all PTFE braided hose.  I have set up and run fuel systems where there is a high pressure 18 to 30 lbs pump from the fuel tank that feeds a return regulator at the engine to drop the pressure, but also required a dead head regulator at the carburretor to ensure idle fuel pressures do not exceed what the needle and seat can handle.  I can see how changes at the regulators effects flow volume, then once the engine is running all that is needed is a slight adjustment of the pressure at the dead head, at idle.
   
For a race engine that has a variable regulator I simulate manifold vacuum pressure at the regulator and can see and set the regulator to supply the engine at wide open throttle without the engine running.  So this testing just proves that the fuel system is capable to supply the volume and can give you confidence that it is working effectively because I can see how the variable regulator reacts to pressure changes. I have found in practice that minior adjustments may be needed at the track, but you are most of the way there doing it this way. Fuel pressure regulators have a sweet spot where a little ajustment give big changes, outside of this and the adjustment scew does stuff all, so you need to know you are in that sweet spot.  The point of all this is, getting to know the fuel system you have installed and pre-configue it before there is any risk in damaging the engine through wildly winding the regulator screw in or out.
 
Typically this service would cost from $1500 give or take, maybe more if there are other issues that need to get sorted.

All work is done at an hourly rate, + parts, + materials.