Advanced Induction Cylinder Head Development
Ai 218cc CNC'd GM 243 LS2/LS6 Cylinder Head Package

GM's #243 casting is a great cathedral head that has phenomenal potential with the right work applied.  Our 218cc CNC work is a good choice for guys who would like a bit more gain than our Performance Rebuild, but are not inclined to port the casting to its potential.  This additional gain is attained via fully CNC porting the exhaust runners, and CNC machining the valve seat area of the intake port.  The remainder of the intake port, and the combustion chamber are left as cast.  Typical gains for our CNC work are in the 20-30rwhp SAE range over the as cast 243.  This option is best for applications where rules do not allow intake work.  For everyone else, the 226cc full CNC work is a better value with no downside.

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 Exhaust, & Combustion Chambers
  • 100% CNC Professional Competition Quality Valvejob
  • Intake's CNC'd Valve Job Blended into As-Cast Port
  • 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: $995

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.

Bronze Guide Liners installed & honed to ideal clearances to refurbish worn out guides. - Cost: $150
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