Small Block Chevy Sportsman II Cast Iron Cylinder Heads - 64cc Combustion Chambers, Angle Plug
Typical Application Street: 274 Cam: 230/236° .487''/.490'', 750 cfm carb, 1-3/4'' header. 430HP on 9.8:1 355; 480HP on 383 10.5:1 (varies with displacement and compression ratio).
Typical Application Drag Race: Modified 750 cfm carb, 276/284° roller cam, single plane plenum intake, 1-3/4''-plus header. MUST Upgrade to 1.550'' roller valve springs and 10° hardware. Up to 650HP normally aspirated depending on displacement and CR and porting.
Material: High density cast iron
Valve Seats: Integral intake,hardened steel exhaust
Valve Guides: Integral cast iron
Valve Spring Seats: Machined for 1.250'' springs
Valve Size: 2.020'' x 1.600''
Exhaust Flange: Stock locations, 7-bolt universal pattern
Included In Assembly: Erson stainless steel valves, ring and band-style seals, valve springs, Erson 7° chrome moly retainers, and keepers.
Head Gaskets: Fel-Pro #1003 ( 265-350 ) or equivalent
Puhshrods: Requires heat-treated pushrods. Use of 1.6 ratio rocker arms require elongation of pushrod holes.
Screw-in Studs: 3/8" or 7/16" with 7/16"-14 base thread
Pushrod Guidplates: Flat 5/16" Erson 601 or equivalent
Spark Plugs: Accepts 14mm .460'' reach tapered seat 5/8'' hex or equivalent
Intake Gasket: Fel-Pro #1205 or equivalent
Exhaust Gasket: Fel-Pro #1404 or equivalent
Maximum Valve Diameter: 2.100'' x 1.600'' or 2.080'' x 1.625''
Maximum Spring Seat Depth (from inside step): .030''
Maximum Spring Diameter: 1.550''
Approximate Milling Guidelines(varies with depth): .0065'' per cc
Maximum Flat Mill Depth (up to intake seats): .040''
Maximum Angle Mill ( approx. 50-52cc volume): .175'' depth
NOTE:These specifications are for reference only. ALWAYS measure before machining.
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