i have the chance to pick up a pretty cheap walbro high flow pump for my lude, my question is if i put it in with the rest for the fuel system stock will the stock fpr still maintain the stock fuel pressure or will the high flow pump cause me to run rich?

im a little confused because im pretty sure that the FPR is what determines the fuel pressure but if you have a more powerful pump will the fpr compensate and keep the stock pressure

Pressure will probably go up around 5 psi...

what makes the presure higher the fact that the stock fpr can't bypass the high flow that the walbro makes?
eventually im going to be boosting 7 psi and i am going to use a FMU becasue i can't aford a standalone, and with an fmu i know i need a higher flow fuel pump becaseu the stock one will drop out like after 4psi with a a rising rate fuel presure regualtor, so i can pick up a walbro cheap and would solve my flow problem but im worred about off boost idle