This is a slightly larger version of our 226cc CNC work that has consistently outperformed other CNC'd GM castings on the market, as well as most aftermarket casting based heads.  The 226cc work being only slightly larger than the as cast port, would often leave some areas in the intake port untouched by the CNC cutting tool.  While this is aesthetic and does not negatively affect performance, this slightly larger version will minimize or eliminate these areas of "non-cleanup." Most applications will not be negatively affected by the slightly larger intake port, and LS2's & strokers will pick up another few HP over the standard 226cc CNC work.

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 Ported Intake, Exhaust, & Combustion Chambers
• 100% CNC Professional Competition Quality Valvejob
• Factory Valves Cleaned & Precision Ground
• PCD milled to ensure flatness, surface finish, & achieve desired chamber volume (57 - 69 cc)
• Intake Flange, Exhaust Flange, and Valve Cover Rail PCD Milled to new surface finish specs

Machining & Labor Cost: $995


Labor and Component Options:

Bronze Guide Liners installed & honed to ideal clearances to refurbish worn out guides. - Cost: $125
Replace OEM guides with Full Bronze Guides & hone to ideal clearances - Cost: $250

PSI 1511 MaxLife Endurance Spring Kit w/ OEM Replacement Seals. - Cost: $250
Manley 23622 Titanium Retainers for OEM, PAC, PSI, etc. beehive springs - Cost: $195
Lunati Gold dual valve spring kit w/ lightweight steel retainers.  Lift capacity to .660" - Cost: $225
BTR .660" Polished Dual Spring Kit w/ locators, viton seals, & Titanium Retainers - Cost: $300

Manley 221436 Nextek .660" shot peened & fully polished Dual Spring Kit:

221436-16 Dual Springs
23623-16 Titanium Retainers
42334-16 Hardened Spring Locators
13098-16 Precision Machined Locks
Steel jacketed Viton seals for dual springs

Cost: $525 bought w/ head work (This is a premium setup that is ~$700 shipped from Summit)

Please Contact Us for shipping & turnaround quotes!