Mr. Gasket
Ultra-Seal Header Gaskets Fits 1955-1991 Chevrolet 262-400 Gen I Small Block Square Ports, 1.45 Inch x 1.55 Inch Mr Gasket
SKU: M00S 5901
Description
Part #: 5901
Manufactured from high-temperature steel core/graphite faced exhaust material. Expanded steel core provides stability and maximum torque retention to eliminate Gasket failure.Graphite facing provides excellent heat resistance and thermal conductivity to transfer heat away from the cylinder head. Conforms to and seals minor surface irregularities.High recovery material allows header or manifold flange to stay sealed if flange loses clamp-load. Can be trimmed if necessary for modified port applications.For original equipment replacement, high performance street, drag race and oval track use.Withstands Intense Exhaust HeatGraphite-Impregnated FacingSteel Expanded Metal CoreSuperior Tensile StrengthResists DeterioratingAnti-stick PropertiesEasy Removal For DisassemblyDetails:Collector Gaskets Included: NoEmission Code: 5Finish: FlatGasket Line: Ultra-SealMaterial: Ultra-sealPort Shape: SquarePort Size: 1.45 x 1.55Warranty: Manufacturer's Limited 90 Day Warranty
Features:
- Withstands Intense Exhaust Heat
- Graphite-Impregnated Facing
- Steel Expanded Metal Core
- Superior Tensile Strength
- Resists Deteriorating
- Anti-stick Properties
- Easy Removal For Disassembly
Exhaust Manifold / Header Gasket - Ultra-Seal - 1.450 x 1.550 in Square Port - Steel Core Laminate - Small Block Chevy - Pair
Fitment
Fitment Guaranteed
Don’t gamble
on fit.
Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.
Available on iOS & Android
Specifications
| Brand | Mr. Gasket |
| Part Number | M00S 5901 |
Buy with Confidence
Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.
View Full Return Policy