Adjustable Fuel Pressure Regulator Question

I bought a set of bigger Injectors for my 90 Model GT Mustang and the fuel pressure is way up..i wanna know how to adjust it. I keep tryin to order an Adjustable Fuel Regulator and they keep tryin to sale me one for a Carborator not Fuel Injection. Is there anybody that can help me out with this? Thank You.

I appreciate the advice that was given..what I did was I took a stock 5.0 HO that i had tuned with vacuum leaks. I was under the impression that the jag off that dyno'd it just added more fuel to compensate for the vacuum leaks that i found during this process, so I pulled the chip. Replaced the intake with a GT40 top and bottom trickflow spacer, SVO heads with 1.6 roller rockers, F303 cam, 70mm throttle body, stock Mass Air Flow....wasnt aware I was supposed to change it to compensate for the Fuel and Air. I bought a MSD Ignition Box 6al will this help hyper-tech coil pack? (Box not installed yet.) So do i just change the Mass Air Flow for the size injectors that i have? And i'll check for the pinched fuel line.
By the way.. How much fuel pressure is too much. It feels like the car should be more responsive..runs good but i think it should be a little more punchy. It used to idle at 38 and now at 43lbs.
And should I go get a new tune for that chip? The dude wanted to charge me another 300 bucks to tune it again. Thanks alot.