This is a difficult question to answer without knowing all the details of the fuel system, but generally speaking it is always better to locate any regulator, fuel, voltage, etc. as close to the point you are trying to regulate as possible.
Bullshark
I don't know what you mean by that, but the regulator should be after the injectors in the loop, thus adjusting the pressure on the pump/injector side by opening and closing the return line fuel flow.
Suppose it doesn't matter much if the ecm/injectors can handle a wide enough range for pressure spikes/peaks.
:withstupid: Don't know why you would want to locate the regulator in the rear. How would you adjust it? Lay on your back with the engine running?

Put the regulator as close to the fuel rails as possible. Most regulators require a return line to be as efficient as possible.
It is a L98 regulator, hooked to a modified LT1 intake on my L98 engine.....
got tired of the L98/TPI setup, reading about modded up LT1 intakes on the net, so decided to try it almost 2 years ago...took a while, but it works fine on first install....
ANYway, the reg went in the rear and I used Aeroquip steel lined fuel hose for the front feed line, blocking the returns entirely....used the return line for the vac signal.....and....
it ran like total DAWG SHIT, idled fine, started easy, WOT was good, but that tip in driving was too much signal lag from vac drop to fuel pressure change....so back up front it went....
but here is what is interesting....from the git go, on the very first install of a TPI on this car I have been using Earls rubber red marked he pressure fuel line hose....never thought much about it one way or another....remember the TPI has long steel tubes from both the input and return lines to the hoses to the frame lines....
so I just used same hose for the LT1 manifold install,
but I noticed the hose pulsed with the injector banks firing....never paid any nevermind to that before...never noticed it....
anyway, this last hookup, reg back up front as normal, I used the steel lined Aeroquip hose for both the rail to the fuel line, pump in rear, from the rail to the regulator, and then back to the return is the old Erols rubber hose....
the pulsing on the hose is gone, feel almost nothing....
and the engine is smoother and more consistent.....for about ten days + now....
seems my rough idle problems were due to a multiplicity of problems.....
water in tank, still unknown how, just was.....which messed up the injectors, new ones from Jsup straightened out a LOT of it....
now the fuel lines, and it's better yet....
God damn sensitive bastard, friggin car is female, no wonder I like riding it so much.....:devil: