Advanced Induction Cylinder Head Development
100% CNC'd 226cc GM LS6/LS2 Cylinder Head Package

GM's #243 or #799 LS6/LS2 head casting is the most sought after GM cathedral port casting.  At a mere 15 cc over stock volume this particular port sees gains of over 40 cfm on the intake utilizing a factory GM 2.00" valve.  This package has found great success amongst enthusiasts seeking area under the curve, phenomenal throttle response, and no loss in drivability.  It has also shown excellent potential in drag applications.  Typical gains are 40-50rwhp over the as cast 243, with most LS1 & LS2's producing 450-500rwhp SAE with daily drivable cams.  Rick Leininger's 5.7L GTO took the NA stock short block record after swapping to our 226cc LS2 heads.  From stock short block 346cid LS1's to 4XXcid strokers, this is a phenomenally versatile head.  For max effort 4" bore and larger applications, larger valves, etc. it is worth considering our 232cc CNC option.

Pricing is for work applied to a pair (2) of cylinder head castings and components YOU supply unless otherwise noted.  We are happy to build your heads with whichever spring kit, valve, etc. you would like.  Please keep in mind if components you provide require additional time on our part, we must bill for that.


Machining & Labor Operations:
  • 100% CNC Ported Intake, Exhaust, & Combustion Chambers
  • 100% CNC Professional Competition Quality Valvejob
  • Valves Cleaned & Precision Ground (whether using new aftermarket or re-using OE GM)
  • PCD milled to ensure flatness, surface finish, & achieve desired chamber volume (57 - 69 cc)
  • Customer can specify milling to an Available P2V Clearance relative to stock (e.g. .018" less P2V)
  • Intake Flange, Exhaust Flange, and Valve Cover Rail PCD Milled to new surface finish specs
  • Thorough Inspection of Castings, Components, Bind Heights for your individual set of springs, etc.
  • Complete Cleaning/Prep including Bead Blasting + UltraSonic to ensure internal passages are clear & free of debris
  • Professionally Setup & Assembled for your individual application - Ready to bolt-on & Run
Machining & Labor Cost: $1195

Please Contact Us for shipping & turnaround quotes.


Labor and Component Options:

Note: GM heads often show so little guide wear that they do not need to be replaced.  In the event they do require attention due to wear or your application, we have several options.  GM OEM valves are high quality, durable, and lightweight.  Most applications do not need an aftermarket valve.

Bronze Guide Liners installed & honed to ideal clearances to refurbish worn out guides. - Cost: $200
Replace OEM guides with Ai Pro Racing Quality Full Bronze Guides & hone to ideal clearances - Cost: $250
Replace OEM guides with new Powdered Metal Guides & hone to ideal clearances - Cost: $250

PSI 1511 MaxLife Endurance Spring Kit w/ OEM Replacement Seals. - Cost: $280
PSI 1516 High Lift MaxLife Endurance Spring Kit w/ OEM Replacement Seals. - Cost: $380
Manley 23622 Titanium Retainers for OEM, PAC, PSI, etc. beehive style springs - Cost: $195
BTR .660" Polished Dual Spring Kit w/ locators, viton seals, & Steel Retainers - Cost: $230
BTR .660" Polished Dual Spring Kit w/ locators, viton seals, & Titanium Retainers - Cost: $300
Manley Nextek .660" rated shot peened & polished Dual Spring Kit w/ Titanium Retainers - Cost: $500
Manley Nextek .700" rated shot peened & polished Dual Spring Kit w/ Titanium Retainers - Cost: $635
Manley Nextek .800" rated shot peened & polished Dual Spring Kit w/ Titanium Retainers - Cost: $700

Manley Race Series Stainless Steel Valves - Cost: $150 Intake OR Exhaust, $300 Both Intake AND Exhaust
Manley Hollow Stemmed Stainless Steel Intake Valves (11-12g lighter than solid stemmed intakes) - Cost: $395
Manley Severe Duty High EGT Stainless Steel Exhaust Valves (High HP power adder applications) - Cost: $250
Manley Extreme Duty High EGT Inconel Exhaust Valves (Max Effort power adder applications) - Cost: $395




Dyno, Flow Bench, and Track Results: