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12615363 - LS6 Bare Cylinder Head, Bare No Springs or Valves

This product may require vehicle validation(s) for proper fitment. Please contact us to confirm correct vehicle fitment and usage.

Availability: Replaced by 12629049


The LS Family Production and C5R Aluminum Heads

Great cylinder-head airflow has been a key enabler of the LS Series exceptional performance. GM Performance Parts delivers those power-building attributes to you with a range of production-style aluminum heads from the LS6 heads for smaller-displacement engines to LS7 style heads for 427-inch-and-larger combinations, our aluminum heads benefit from General Motors extensive research and development program, ensuring maximum airflow without compromises. In fact, many professional builders use our heads as straight bolt-ons, with no further machining. Many of our assembled heads use premium machining and materials, including CNC finishing and porting, along with lightweight, hollow-stem valves, sodium-filled exhaust valves and on some heads lightweight titanium intake valves.

Aluminum LS Family Head Technical Notes:

  • Manufactured from 319-T5 aluminum alloy
  • High-efficiency combustion chambers
  • Symmetrical intake and exhaust ports
  • Angled spark plugs (14mm; 5/8" hex; " reach; taper-seat plugs)15 valve angle
  • Bolt-down-type rocker arms
  • Center-bolt valve cover hold-downs
  • Fits Gen III and Gen IV Small-Blocks only*

LS6 Bare Cylinder Head

  • 2.00" intake, and 1.55" exhaust
  • 210cc cathedral port intake ports
  • 70cc D-shaped exhaust ports
  • 65cc combustion chambers

Application List



  • 12615363
  • 12615363
  • GM (General Motors)
  • Replaced by 12629049
  • New


Shipping Information

  • Item Requires Shipping
  • 22.1 lbs.
  • W8.5000” x H6.4000” x L21.2000”

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