Dorman Autograde Brass Cup Engine Expansion Plug 1-3/8 In for 1955-1959 GMC and 1955-1957 Pontiac 565-025

Brass cup engine expansion plug 1-3/8 inch diameter for 1955 to 1959 GMC and 1955 to 1957 Pontiac used to replace leaking or corroded factory freeze plugs.

Built to meet the manufacturer's design intent for reliable service, this expansion plug is constructed from quality brass materials to resist corrosion and ensure a tight seal within the engine block.

Key Features

• Constructed from durable brass for long-lasting performance
• Precise 1-3/8 inch diameter with 0.310 inch height
• Designed to match original equipment form and function
• Engineered for direct fit installation on specified models
• Validated by product experts with over a century of automotive experience

Benefits

• Stops coolant leaks caused by worn or damaged factory plugs
• Resists rust and corrosion better than standard steel plugs
• Reduces the risk of repeat repairs with reliable materials
• Ensures proper engine cooling system integrity
• Provides a cost-effective solution for engine maintenance

Application

Ideal for classic car restoration projects and routine maintenance on vintage GMC trucks and Pontiac vehicles requiring replacement of core plugs in the engine block.

Fitment Notes

• Compatible with 1955-1959 GMC models
• Compatible with 1955-1957 Pontiac models
• Verify engine block requirements before purchase

Why Choose Dorman - Autograde?

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

What's in the Box

• 10 Piece Set of Brass Cup Expansion Plugs

Item Dimensions

• 3.2 inches x 2.4 inches x 1.5 inches
• Weight: 0.5 lbs