GM's new LS3 head represents a phenomenal leap in capacity over previous cathedral port castings.  In as-cast for this head moves only ~310 cfm at a whopping 260 cc port volume.  Keeping in mind that the LS3 is already a relatively large port we have decided to offer our full CNC porting in several sizes.  While there is not a large performance difference from 270cc to 280cc, there is a significant difference in port cleanup.  The smaller 270cc size is capable of producing an easy 600hp+ on mild builds, and has proven it will make 700hp+ on 40Xcid+ engines below 7krpm with HR cams.  However, due to significant core shift in the GM castings, there are often large areas that remain as cast.  While it does not negatively affect function, some are bothered by the aesthetics.  Those customers should request the larger 280cc version to reduce the size of areas untouched by our CNC program.  The 280cc version is always preferable for high RPM power, or high displacement builds.  Due to the efficiency of the port design, none of the options negatively affect drivability, and all are typically within 10-15hp of one another in most applications.

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

Ai 280cc CNC'd heads including New GM LS3 821's with the Hollow LS3 intakes: $3395 + Spring Setup
We keep these in stock so they can be milled to your desired volume or valve drop, built with an appropriate spring setup (add one from below), and shipped by the time your payment clears.  A great option for guys who lack good cores to use as a base, want all new parts, or cannot wait to have their own heads ported.  Suggested setup: Add a PSI Maxlife Beehive 1511 ($320) or 1516 ($360) for typical Hydraulic Roller use.

Please Contact Us for shipping & turnaround quotes.


Labor and Component Options:

Note: GM LS1/2/3/6 guides 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 (heat, etc.), we have several options.  GM OEM valves are generally high quality, durable, and lightweight.  Most naturally aspirated hydraulic roller applications do not necessarily need an aftermarket valve.  In many cases, common entry-level aftermarket valves are a significant downgrade.  If you have "extra" $ to spend, upgrade springs & components first, and invest in our high quality valve options for durability, performance, and safety margin second.  If budget allows, doing both is worth the $, particularly in the long-term.

Suggested Setups -

• Long-Term Mild Street Toy to DD:  PSI 1511's, ~.600" net lift or under.  Retain OE guide & valve set if in good condition.
  
• Typical Street Hot Rod:  BTR Duals, or upgrade to PSI's or PSI's w/ our Lwt Retainers if budget allows.  Typically ~.6XX" net lift.
  
• Aggressive Hyd Roller:  PSI UHR Spring Kit, Possibly one of our PSI Pro Kits depending on application.  ~.6XX-.7XX" net lift.
  
• Solid Roller:  Long-term mild, aggressive street, to full race engineered valve-train systems, etc. - P.O.R., Quoted Per Application
  
• Camshafts:  Have something made for your specific setup & goals.  Guaranteed compatibility.  100% QC Inspection.
  
  Other setups are available for racier applications, compliance with class rules, etc. (e.g. PSI duals & our professional racing grade components, Xceldyne components, Jesel rocker systems, etc.).  All of these will be set up ideally to ensure you maximize the potential that any given components offer.

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 Ai Pro Racing Quality Custom Guides - Material & Dimensions per application - Cost: Quoted Per App

Ai PSI 1511 MaxLife Endurance Springs w/ Hardened Steel Locators & Viton Seals. 100% QC - Cost: $385
Ai PSI 1516 High Lift MaxLife Endurance Springs w/ Hardened Steel Locators & Viton Seals. 100% QC - Cost: $410
Ai Ultimate HR Kit w/ PSI MaxLife High Lift springs + Ai Lwt Tool Steel Retainers, Machined Locks, Locators, 100% QC - Cost: $600
Ai Pro-Series PSI Dual Spring Kit w/ Professional Racing Quality Components, .6XX" Lift w/ Stock Rockers. 100% QC - Cost: $995
Ai Pro-Series PSI Dual Spring Kit w/ Professional Racing Quality Components, .6XX"-.7XX" Lift HR or SR. 100% QC - Cost: $1195

Ai Lightweight Tool Steel Retainers for beehive style springs. Lighter than Ti Dual Spring Retainers - Cost: $195
Manley Titanium Retainers for OEM, PAC, PSI, etc. beehive style springs - Cost: $235
BTR .660" Polished Dual Spring Kit w/ locators, viton seals, & Titanium Retainers - Cost: $310
Manley Nextek .660" rated shot peened & polished Dual Spring Kit w/ Titanium Retainers - Cost: $435
Manley Nextek .700" rated shot peened & polished Dual Spring Kit w/ Titanium Retainers - Cost: $735
Manley Nextek .800" rated shot peened & polished Dual Spring Kit w/ Titanium Retainers - Cost: $860

Manley 'Race' Series, Good Quality Stainless Replacement Valve Set + Ai Prep - Cost: $400
Ferrea 6000 Series, Better Quality Stainless Replacement Valve Set + Ai Prep - Cost: $450
Ai Custom Designed Max Effort Hollow Stemmed Stainless Intake & Exhaust Valves for NA applications - Cost: Quoted Per App
Ai Custom Designed Max Effort Hollow Stemmed Intake & Inconel Exhaust Valves for high EGT applications - Cost: Quoted Per App
Ai Custom Designed Titanium Intake + Coatings & Ai Custom Hollow Steel OR Ai Custom Inconel Exhaust Valves - Cost: Quoted Per App