Click on image to zoom

88958665 - LS6 CNC Ported Cylinder Head - Replaced By 88958622

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

Availability: Item has been discontinued and is no longer available


If you have a 4.8,5.3,5.7 or 6.0L Gen II (LS6 design) engine and want to improve the power output, bolt on a new set of new GM performance Parts Ported LS6 heads. These heads have the same CNC porting as the 88958622 race heads, but the deck has been planed just enough to maintain the production 65cc combustion chamber volume and 10.5: compression ratio. Loaded with premium hollow stem valves,chromium silicone ovate wire valve springs and the rest of the quality LS6 parts. These heads will support 500+ h.p.
  • Complete Cylinder Head with springs and valves.
  • Price shown is for 1 cylinder head
  • Aluminum
  • Combustion chamber volume 65cc
  • Intake runner volume 250cc
  • Exhaust runner volume 85cc
  • Intake valve diameter 2.00"
  • Exhaust valve diameter 1.55"
  • Intake valves are lightweight hollow stem design
  • Exhaust valves are sodium filled for improved cooling
  • CNC Port work done by Lingenfelter
  • Special LS6 valve springs good for .570" lift

Intake Lift CFM

Application List



  • 88958665
  • 88958665
  • Chevrolet Performance Parts
  • Item has been discontinued and is no longer available
  • New


Shipping Information

  • Item Requires Shipping
  • 27.0 lbs.
  • W8.7000” x H6.1000” x L21.5000”

Trusted Specialists GM engine & parts specialists
Located in the USA Owned, operated, & employed
Need Assistance? Call us at 888-748-4655
Mon-Thu 8am-6pm EST
Fri 8am-5:30pm EST
Have a Question Email us and we'll get back to you within 24 hours
Pace B2B