Flow Data

ProMaxx 3146A XXTREME Assembled Cylinder Heads Features:

• High-flow as-cast port design
• Ultra-smooth 356-T6 aluminum casting
• 21-4N stainless 1 piece swirl polished back cut valves
• 5-angle valve job
• 11-Degree valve angle
• Hardened steel valve seats
• OEM LS3 valve spacing
• Manganese bronze diamond honed guides
• Viton valve seals
• Built-in raised valve cover rail
• .750 in. deck thickness
• Billet LS3 OEM rocker stand
• For use with standard or 6 bolt pattern
• Large spring pockets

ProMaxx 3146A XXTREME Assembled Cylinder Heads Notes:

• Requires 3.898 in. minimum engine cylinder bore
• Requires LS3 intake rocker arms
• Included valve springs with tool steel retainers specs:
  • Closed: 155 lbs. @ 1.800 in.
  • Open: 425 lbs. @ 1.150 in.

Emissions Note:

This part is only legal for sale and use on Uncontrolled (Non-Emissions Controlled) Vehicles or on vehicles used solely for the purposes of closed competition racing.

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