Speedmaster PCE348.1009 BBC MLS Head Gasket Bore Thick - 454 4.380 0.040

The Speedmaster PCE348.1009 is a high-performance multi-layer steel (MLS) head gasket engineered for big block Chevy 454 engines with a 4.380-inch bore diameter and 0.040-inch compressed thickness. This single gasket utilizes advanced steel laminate construction designed to withstand extreme cylinder pressures and temperatures in high-horsepower applications.

Key Features:

• Multi-layer steel construction with high-pressure laminate design for superior durability
• 4.380-inch bore diameter and 0.040-inch compressed thickness for precise fitment
• Internal embossments that expand under heat to enhance sealing performance
• Engineered to handle high shearing forces between aluminum heads and iron blocks
• Ideal for turbocharged, supercharged, and nitrous oxide applications
• Superior torque retention compared to conventional composite gaskets
• Minimal distortion under extreme combustion pressures

MLS gaskets maintain consistent contact pressure between the cylinder head and block throughout the full range of engine operation, making them the preferred choice for serious performance builds. Compatible with both aluminum-to-iron and aluminum-to-aluminum block configurations, this gasket delivers reliable sealing in the most demanding racing and street performance environments.