L92 Cylinder Head Assembly


  • 319-T5 aluminum alloy
  • 2.165″ solid stem intake, and 1.590″ solid stem exhaust valves
  • .510″ max valve lift
  • For any LS family engine with 4.000″ bore or larger


SKU: 12629062 Categories: ,

L92 Cylinder Head Assembly

P/N 12629062

– Aluminum performance head
– Fits any LS family engine with 4.000″ bore or larger
2.165″ solid stem intake, and 1.590″ solid stem exhaust valves
.510″ max valve lift
– As-cast L92 style intake ports
– D-shaped exhaust ports
– As-cast combustion chambers

L92 Head Flow Data (4.000″ Bore):

Lift 0.200″ 0.300″ 0.400″ 0.500″ 0.600″
Intake 151 208 256 294 316
Exhaust 111 152 174 183 189

Replaces old P/N 12629064.


L92 Cylinder Head Assembly

12629062 Chevrolet Cylinder Head

LS Family Engines with 4.000″ Bore or Larger

Great cylinder-head airflow has been a key enabler of the LS-Series‘ exceptional performance. Chevrolet Performance delivers those power-building attributes to you with a range of production-style aluminum heads ヨ from the LS6 heads for smaller-displacement engines to LS7 style heads for 427-inch-and-larger combinations, our aluminum heads benefit from GM‘s 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 ヨ on some heads ヨ lightweight titanium intake valves.

Aluminum LS Family Head Technical Notes:
ユ Manufactured from 319-T5 aluminum alloy
ユ High-efficiency combustion chambers
ユ Symmetrical intake and exhaust ports
ユ Angled spark plugs (14mm; 5/8″ hex; 3/4″ reach; taper-seat plugs)
ユ 15ᄚ valve angle (except C5R and LS7)
ユ Bolt-down-type rocker arms (except LSX-DR, LSX-CT)
ユ Center-bolt valve cover hold-downs
Fits Gen III and Gen IV Small-Blocks only

NOTE: Chevrolet Performance heads will not fit 4.8L and 5.3L engines, due to their smaller bore sizes.

Replaces old P/N 12629064.

Prop65WARNING: These auto parts can expose you to chemicals including phthalates and lead. Installing or using these parts can expose you to other parts containing these chemicals and to engine exhaust, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to