GM's #243 or #799 LS6/LS2 head casting is the most sought after GM cathedral port casting.  This CNC option was designed and produced several years ago specifically for Grand-Am Daytona Prototype competition where 230 cc is the maximum port volume allowed.  As our current race pieces are revised, we release these designs to the public.  At a mere 15 cc over stock volume this particular port sees gains of over 40 cfm on the intake utilizing a factory GM 2.00" valve.  This package has found great success amongst enthusiasts seeking area under the curve, phenomenal throttle response, and no loss in drivability.  It has also shown excellent potential in drag applications.  Typical gains are 40-50rwhp over the as cast 243, with most LS1 & LS2's producing 450-500rwhp SAE with daily drivable cams.  Rick Leininger's 5.7L GTO took the NA stock short block record after swapping to our 226 cc LS2, and the current fastest NA AWD TBSS runs this exact head.  From stock short block 346cid LS1's to 4XXcid strokers, this is a phenomenally versatile head.

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


Casting Options:

New GM LS2 243/799 Heads w/ OEM Components - Cost: $775


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

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!