Used to replace an engine that requires an integrated fuel pump. Stock 1988 GM 5.7L tbi requires 10-16psi. Called Carter's tech. Said it was what I need for a stock engine. As other people say I need a built in regulator. The standard engine runs too rich. Until the end. We will keep you informed. Secondly. The fittings provided are for 1/2" fuel hose. In most cases, a 3/8" diameter should be more than enough. The unit came with rubber isolation pads to reduce vibration transmission.