Advanced Induction Cylinder Head Development
Ai GM 823 L92 Performance Rebuild Cylinder Head Package

Our Performance Rebuild suite of inspection and machine work is a great option for the value minded.  Even in as cast form the GM L92 castings are capable of producing impressive power levels.  If you are building a budget 475-550hp setup, it is difficult to beat the value of bringing the factory head back into better than new condition.  Our precision valve grinding and CNC'd valve jobs are a great way to pick up some power and ensure your heads are ready to go for tens of thousands of miles.

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.


Machining & Labor Operations:
  • 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
  • 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.
  • Deburring of Entire Casting + fine detail softening of all edges in & around combustion chambers
  • 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: $995


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: $250
Replace OEM guides with Ai Pro Racing Quality Full Bronze Guides & hone to ideal clearances - Cost: $295
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: $340
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: $400
Manley Nextek .700" rated shot peened & polished Dual Spring Kit w/ Titanium Retainers - Cost: $660
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




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