Ultra-Seal is Mr. Gasket premium valve cover gasket material. It's manufactured from a high density cork and rubber blend with a black latex coat applied to the outside to help seal minor flange irregularites and eliminate oil leakage.
Mr Gasket Engine Valve Cover Gasket Set 274; for Ford 351M/400
Mr Gasket Engine Valve Cover Gasket Set 5876; for Chrysler 273-360 "LA" Mopar
Mr Gasket Engine Valve Cover Gasket Set 378; for Chrysler 361-440 B/RB Mopar
Mr Gasket Engine Valve Cover Gasket Set 5871; for Ford 351M/400
Mr Gasket Engine Valve Cover Gasket Set 278; for Ford 429/460 BBF
Mr Gasket Engine Valve Cover Gasket Set 585G; for Chevy 262-400 SBC