The EC Carburetors designed Copper Head Gasket fits the Briggs & Stratton Model 31 OHV Engine. 

Copper Gaskets have excellent durability by distributing heat evenly to minimize distortion provides a better seal for high-compression, modified engines. For extreme builds needing better seal and less likely to blow on higher compression engine, use Edelbrock Gasgacinch sealant. Sold separately