Dorman Autograde Steel Cup Expansion Plug 1-1/8 Inch for Buick Chevrolet GMC Oldsmobile Pontiac 555-020

Steel cup expansion plug 1-1/8 inch for Buick Chevrolet GMC Oldsmobile and Pontiac engines used to replace worn or leaking factory cylinder head plugs.

Built to meet the manufacturer's design intent for reliable service using quality steel materials engineered for durable performance in demanding engine environments.

Key Features

• Constructed from durable steel for long-lasting resistance to corrosion and heat
• Precise 1-1/8 inch diameter with 0.470 inch height for accurate fitment
• Designed as a direct replacement for original equipment cylinder head plugs
• Compatible with multiple vehicle brands including Buick Chevrolet and GMC
• Part number 555-020 ensures correct identification for ordering

Benefits

• Restores engine sealing integrity to prevent coolant leaks and overheating
• Reduces the risk of repeat repairs through robust material construction
• Ensures proper fit without modification for smoother installation
• Helps maintain optimal engine operating temperature and performance
• Provides a cost-effective solution compared to dealer-only parts

Application

Ideal for mechanics and DIY enthusiasts repairing engine cooling systems on older GM vehicles requiring replacement of failed or corroded expansion plugs in the cylinder head.

Fitment Notes

• Fits Buick models from 1975 to 1988
• Fits Chevrolet models from 1978 to 1984
• Fits GMC models from 1978 to 1984
• Fits Oldsmobile models from 1975 to 1988
• Fits Pontiac models from 1976 to 1988

Why Choose Dorman - Autograde?

• Dorman parts are engineered as direct-fit replacements designed to match OE form fit and function
• Backed by a team of product experts in the United States and over a century of automotive experience
• Built with quality materials and validated through testing to stand up to daily driving demands

What's in the Box

• 10 PC

Item Dimensions

• 3.7in x 2.4in x 2.2in 0.4lbs