Severe Duty Exhaust ValvesSmall Block Chevy1.600 Diameter11/32 (0.3415) Stem Diameter4.911 Overall Length (Stock)10� x 3/8 Underhead Angle/RadiusStainless Steel8/pkg. Type: Exhaust Valve XH-428 MaterialHead Diameter: 1.600Stem Diameter: 11/32 / 0.3415Installed Height: StockOverall Length: 4.911Tip Length: 0.250Underhead Angle / Radius: 10° x 3/8Margin: 0.060Seat Width: 0.100Top of Head: 7° DishWeight / Grams: 95