I concur with Evan... in fact, I have documentation that a significant pressure loss was caused by the Prime-Loc system, imposing a hardship on my already weak OE lift pump which could have caused premature failure of my VP44 injection pump if not caught in time. Removal of my Prime-Loc resulted in a minimum 5 psi (across the board) increase in pressure... this was with the specified Fleetguard fuel filter (new). Without going into all the particulars, before I removed the Prime-Loc system I saw a vacuum at the VP44 injection pump at light to light moderate throttle whereas, after the removal of the Prime-Loc system I saw positive flow pressure.
Keep in mind I'm not bashing the Prime-Loc fuel filter relocation system per se, just this system in conjunction with the OE fuel delivery system of the 24v engines.
Also noteworthy, I noticed Geno's Garage dropped the 24v Prime-Loc kit from their catalog.