Dorman 555-074 Engine Expansion Plug

Engine Core Plug for Ford and Mercury Applications

Dorman 555-074 is a steel cup-type engine expansion plug built to match the fit and function of the original part on specified vehicles. It is made from quality materials for reliable sealing in engine core plug locations, including Thermactor hole applications on select Ford and Mercury models.

For buyers searching for a Ford F-150 engine core plug, Ford Bronco expansion plug, or Mercury Marquis engine plug replacement, this part number 555-074 provides an OE-style service solution with direct-fit dimensions.

Key Features

• Steel construction for durable engine sealing performance
• Cup-type design for a factory-style fit
• Maximum diameter: 0.526 in.; minimum diameter: 0.518 in.
• Matches original part fit and function on specified vehicles
• Cross-references Dorman 376301S and EPC-95 for the same application

Detailed Description

This Dorman engine core plug is designed for service on a wide range of Ford and Mercury vehicles from 1967 through 1996, including Ford E-150 Econoline, E-250 Econoline, E-350 Econoline, F-100, F-150, F-250, F-350, Bronco, and Mercury Cougar, Grand Marquis, Marquis, Montego, and Colony Park applications. The steel cup-type construction helps restore the sealing surface in the engine block where a worn or missing expansion plug can lead to coolant loss and contamination concerns. If you need Dorman 555-074 for a Ford E-350 Econoline Club Wagon or Mercury Grand Marquis engine repair, this part is built for the specified opening dimensions and original-style service.

What This Part Helps Address

• Coolant leakage from a damaged or corroded core plug
• Loss of engine block sealing at the expansion plug opening
• Service replacement for missing or deteriorated Thermactor hole plugs
• Fitment issues caused by incorrect plug diameter
• Restoration of factory-style engine block sealing on listed Ford and Mercury models

Installation Notes and Tips

Verify the engine block opening size before installation and confirm the vehicle application against the fitment list. This part is used in specified Ford and Mercury engine core plug locations, so proper surface preparation and correct seating depth are important for a secure seal. Review the vehicle notes carefully for applications that call for one or two plugs at the specified location.

Quality Assurance

Dorman manufactures this expansion plug as a direct replacement part engineered to match original fit and function on listed vehicles. The steel construction and OE-style dimensions support consistent service in engine hardware applications.