Manley Extreme Duty Series performance steel valves are a great choice for supercharged, alcohol-burning, or high-revving engines. These engines generate a lot of heat and require special valves that can handle that kind of punishment. All valves are made from the best stainless steel available, with chrome stems and hardened valve tips. Extreme Duty Series valves are swirl-polished and fully machined and available with either undercut heads or straight stems.

More From This Category

MANLEY Valve, Race Flo, Intake, 33.5 mm Head Dia, 5.5 mm Stem Dia, 102.40 mm Length, For Honda, Each

MANLEY Valve, Race Flo, Intake, 33.5 mm Head Dia, 5.5 mm Stem Dia, 102.40 mm Length, For Honda, Each

$49.91

MANLEY Valve, Extreme/Severe Duty, Intake, 1.378 in. Head Dia, 0.2355 in. Stem Dia, 4.8 in. Length, Gen II, Each

MANLEY Valve, Extreme/Severe Duty, Intake, 1.378 in. Head Dia, 0.2355 in. Stem Dia, 4.8 in. Length, Gen II, Each

$72.68

MANLEY Valve, Race Master, Exhaust, 1.75 in. Head Dia, 0.3715 in. Stem Dia, 5.105 in. Length, For Chevrolet 409, Each

MANLEY Valve, Race Master, Exhaust, 1.75 in. Head Dia, 0.3715 in. Stem Dia, 5.105 in. Length, For Chevrolet 409, Each

$47.58

MANLEY Valve, Pro Flo, Intake, 2.205 in. Head Dia, 0.3133 in. Stem Dia, Hollow Stem, 5.2 in. Length, For Chevrolet LS7, Set of 8

MANLEY Valve, Pro Flo, Intake, 2.205 in. Head Dia, 0.3133 in. Stem Dia, Hollow Stem, 5.2 in. Length, For Chevrolet LS7, Set of 8

$1,400.44

MANLEY Valve, Race Master, Exhaust, Bead Loc, 1.625 in. Head Dia, 0.3125 in. Stem Dia, 4.925 in. Length, For Chrysler HEMI, Set of 8

MANLEY Valve, Race Master, Exhaust, Bead Loc, 1.625 in. Head Dia, 0.3125 in. Stem Dia, 4.925 in. Length, For Chrysler HEMI, Set of 8

$400.37

MANLEY Valve, Severe Duty, Intake, 2.055 in. Head Dia, 0.3415 in. Stem Dia, 5.14 in. Length, Set of 8

MANLEY Valve, Severe Duty, Intake, 2.055 in. Head Dia, 0.3415 in. Stem Dia, 5.14 in. Length, Set of 8

$601.81