Ready-to-Go Race Head for GX390, 420cc, and 460cc
Uses aftermarket GX390 style large-port casting. Heads are ported, bead blasted, flowed, and milled. Heads can be fitted with either single or dual springs. Single springs are recommended for 306 and smaller cams; dual springs are recommended for 307 and larger cams.
Choose a 36 or 40mm Intake Valve, comes with 32mm Exhaust Valve.
Increased milling can increase compression, but at the expense of reliability. ** .120 Not Recommended.
Product Includes:
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Ported & Bead Blasted Head, Milled to Specs
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Oversize Stainless Intake & Exhaust Valves
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Aluminum or Titanium Retainers
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Split Keepers
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HD Single or Dual Springs
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Valve Spring Shims
- 3-Angle Valve Job
