Standard size replacement. Dimensions: 1.813" head dia. x .309" stem dia. Standard overall length. Severe Duty valves. Proven quality over many years. Manufactured from high temperature stainless alloy to a perfect finish. Manley valves feature swirl polished, performance orientated shapes and durable chrome plated stems. Up to 30% weight reduction over stock components. Manley's 'Severe Duty' valves insure a stable valve train, even at high R.P.M.'s.