Yes the 3.0 does run low, appearantly by design. Specs on All Data, FSM , etc. allow normals like around 15psi. Seemed too low to me but that's what's written.
My pump is a Melling , too,,,at least the gears are. The gears have around 45k on them , the body must be at 75k.

dave h.
'89 Raider V6 5spd;Aisin Hubs;; Gen2 LS: frt. brakes, rear coils;U.C.arms;R.trailing arms;idler arm; rear LSD axle w.disc brakes ;2 battery system for Dog's fan; relocated ECU; custom bumpers;J.Baker receiver;Conferr roofrack; t-bar crank.