GM's new L92 head represents a phenomenal leap in capacity over
previous cathedral port castings. In as-cast for this head
moves only 313 cfm at a whopping 260 cc port volume.
Keeping in mind that the L92 is already a relatively large port
our 267 cc CNC'd package focuses on greatly increasing it's
efficiency. Serious enthusiasts, racers, and some of the
premier tuning shops in the country are reporting excellent
gains thus far. What sets this package apart from many
ported L92 heads is the capacity for significant gains without
sacrificing drivability, throttle response, and power below
5,000 rpm. While the power gains are impressive, the
largest gains are often realized in the meat of the power band.
Where many ported L92's on factory short blocks are in the
mid 400's for peak torque, we've seen in excess of 480 rwtq SAE!
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 (62 - 73 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
- Deburring of Entire Casting + fine detail softening of all edges in & around combustion chambers
- Professionally Setup & Assembled for your individual application - Ready to bolt-on & Run
Machining & Labor Cost:
$1795
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