Technical Specifications of...
Motown 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: 2.080" x 1.600"
Rocker Arm Studs: Screw-in style with hex (3/8" for - 2 models, 7/16" - 3 models)
shoulder furnished with assembly
Accessory Flange: Stock locations. 7-bolt universal pattern
Included In Assembly: Manley stainless steel valves with swirl-polished heads, umbrella (-2 models) or PC (-3 models) style seals, 1.437" (-2 models) or 1.550" (-3 models) valve springs, Manley 7° (-2 models) or 10° (-3 models) 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 5/8"hex tapered seat (Accel 276 or equivalent)
Intake Gasket: Fel-Pro #1205 or equivalent
Exhaust Gasket: Fel-Pro #1404 or equivalent
Machine Shop Specifications:
Maximum Valve Diameter: 2.125" x 1.600" or 2.100" x 1.625"
Maximum Spring Seat Depth (from inside step): .030"
Maximum Spring Diameter: 1.550"
Approximate Milling Guideline (varies with depth): .007" 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.