Technical Specifications of...
Sportsman II Cast Iron Cylinder Heads

Material: High density cast iron
Valve Seats: Integral intake, hardened steel exhaust
Valve Guides: Integral cast iron
Valve Spring Seats: Machined for 1.250/1.550" springs (stepped)
Valve Size: 2.020" x 1.600"
Rocker Arm Studs: 3/8" (-1 & -2), 7/16" (-3) Screw-in style
Accessory Flange: Stock locations. 7-bolt universal pattern
Included In Assembly: Manley stainless steel forged valves with swirl-polished heads, umbrella valve seals (-1 & -2), PC-style (-3),1.250" (-1 models). 1.437" (-2 models) or 1.550" (-3 models) Hardcore valve springs, Manley 7°

(-1 & -2), 10° (-3) chrome moly retainers and keepers.
Recommended Installation Items:
Head Gaskets: Fel-Pro #1003 (265-350) - #1004 (400) or equivalent
Pushrods: Requires heat-treated pushrods. Use of 1.6 ratio rocker arms requires elongation of pushrod holes.
Spark Plugs: Accepts 14mm .460" reach tapered seat 5/8" hex Accel 276, Champion #670 or #802 - or equivalent)
Intake Gasket: Fel-Pro #1205 or equivalent
Exhaust Gasket: Fel-Pro #1404 or equivalent