Mercury Grand Marquis 1990-1991, Seal-4-Good™ Exhaust Header Gaskets by Percy's High Performance®. The Percy's Seal-4-Good Reusable Flange Gaskets are multi-layered and made from a special "Dead Soft" Aluminum, which conforms to header flanges for the ultimate seal. Since the Seal-4-Good is made from multiple layers of dead soft metal, it easily conforms to small imperfections that a copper gasket simply can not. Due to this construction, these gaskets will not blow out or burn out when properly installed. These extreme high-temperature gaskets are well-suited for highly-modified engines: turbocharged, supercharged, nitrous or fuel. This is a premium, high-performance gasket at an affordable price.
Fitment notes: Fits Models with Small Block Engines 221-302-351W.
- Malleable stainless steel metal core
- Will survive 2000°F exhaust temperatures for extended periods
- Carbon felt material on a stainless steel core
- Graphite composition sealing material for high heat applications
- Malleable core conforms to gasket flange for leak-free sealing
- Easily port-matched to modified heads
- Seals even imperfect flanges
- Made in U.S.A.
The extremely high exhaust temps modified engines produce make it tough for a conventional gasket to survive. XX Carbon gaskets are made of 100% carbon-felt material embossed on a steel core; there's nothing to burn out. This material withstands long term exposure to over 2000°F; this makes for a long-life gasket! The XX Carbon line of gaskets offers superior sealing ability even on the worst flange surfaces.