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: 1.600''Stem Diameter: 11/32'' / 0.3415''Installed Height: StockOverall Length: 4.911''Tip Length: 0.250''Underhead Angle / Radius: 10° x 3/8''Margin: 0.060''Seat Width: 0.100''Top of Head: 7° DishWeight / Grams: 95