Fel-Pro 1143 is an MLS performance head gasket for Gen I Chevy small block V8 engines, built to seal performance combinations where cylinder pressure, heat, and head movement can overwhelm a conventional replacement gasket. Its multi-layer steel construction, bore beads, and coolant-passage sealing beads focus clamp load where the engine needs it, making it a strong choice for high-compression, supercharged, turbocharged, or nitrous-assisted small blocks.

Fel-Pro 1143 Technical Specifications:

• MLS construction uses multiple steel layers to support sealing integrity in high-cylinder-pressure small block applications.
• 4.165 in. bore diameter, 105.791 mm metric equivalent, provides coverage for common Chevy small block V8 bore combinations.
• .041 in. compressed thickness and 9.2 cc compressed volume help builders account for quench and compression calculations.
• Multi-layered steel bore bead combustion seal concentrates clamp load around each cylinder without a lock wire.
• Strategically placed sealing beads around coolant passages help resist fluid leaks when the cylinder head moves under load.
• Designed to tolerate scrubbing between dissimilar materials, including aluminum cylinder heads on cast-iron engine blocks.
• Not intended for use on emission-controlled vehicles.

Includes:

• One head gasket

Well suited for performance rebuilds using higher compression ratios, aggressive cam timing, elevated operating temperatures, forced induction, or nitrous oxide. Verify surface finish, fastener selection, and final compression calculations as part of engine assembly.

Fits Gen I Chevy small block V8 engine families including 262, 265, 267, 283, 302, 305, 307, 327, 350, and 400 ci builds. The 4.165 in. bore size can also be used on 400 race engines with up to a 4.155 in. maximum bore and minimal chamfer.