Nearly 30 years of obsessively cataloging, photographing, and taking video of each part means it will fit your 1978 Mercury Marquis 5.8L Engine - OE Style Pump - Standard Pump has 1 Pressure Line 1 Return Line - with Ford Pump - with Vacuum Booster Power Steering Pump.
Period. No Hassle. GUARANTEED.
We cover round trip shipping if we make a mistake.
Check out the video below to view the Guaranteed Exact Fit process from start to finish!