DieselSite's HIGH VOLUME Low Pressure Oil Pump will fit the 1994-2003 7.3L PSD. This high volume LPOP supplies more volume to handle the higher demands of larger HPOPs. Also provides additional oil for twin turbos. Most importantly, it will provide a better supply of lubricating oil to protect your engine with better lubrication and cooling to main bearings and piston oilers.DieselSite set out to make not only a larger pump, but also a better built pump. Each set of gears is custom cut, ground, and polished as a set. This insures perfect mating from gear to gear and from the gears to both the front cover and the timing cover. This insures less wear and better efficiency. We have seen the "off the shelf" aftermarket replacement pumps be out of parallel from the back to the front surface of the pump as well as the mounting surface to be machined so poorly that they wobbled on a flat surface. They rely on the gasket to seal (which it does), but that surface inconsistency allows the gears to move in an undesirable manner. This could cause low oil pressure, and in extreme cases, scoring or damage to the timing cover. This HV LPOP (high volume low pressure oil pump) includes the new front cover with dual lip viton seals, new pump cover to front engine cover gasket, and new oil pump gears designed to increase flow and pressure while reducing cavitation. Installation is simple requiring only a few basic tools as well as a fan removal tool and a harmonic balancer puller. (these can be rented/borrowed from a local Auto Parts Store if you don't own them) Install time is about 2 hours. No other modifications must be made. This can be bolted onto any configuration from stock to highly modified engines.