GM LS2 LS6 #243 Cylinder Head 12564243 6.0 5.3 5.7 Cathedral Port SET OF 2 For Sale

This is an OEM GM aluminum cylinder head with the desirable 243 casting, used on high-performance LS2 and LS6 engines and a direct bolt-on upgrade for many 4.8L, 5.3L, 5.7L, and 6.0L LS-based truck motors. These heads are known for excellent airflow, ~64cc combustion chambers, and cathedral intake ports that flow better than 241/853 heads.

Condition

• Used, inspected core

• No visible cracks

• No broken or missing rocker bosses

• Surface and valve condition should be inspected before installation

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✔ OEM PART NUMBERS & REFERENCES

• GM OEM Part Number: 12564243

• Casting Number: 243

• Interchange/Service Replacements: 12562317, 12562319, 12629058, 12572035

• Equivalent design to 799 casting (same ports & chambers)

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✔ FEATURES

• Cathedral-Port Intake

• ~64cc Combustion Chambers

• Intake Port Volume: ~210cc

• Exhaust Port Volume: ~75cc

• Valve Sizes: 2.00” intake / 1.55” exhaust

• Aluminum construction

• Works on both Gen 3 and Gen 4 LS engines

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✔ VEHICLE FITMENT

Buyer must verify fitment with VIN, but commonly used on:

Performance Cars

• 2001–2004 Corvette Z06 (LS6)

• 2005–2007 Corvette (LS2)

• Pontiac GTO (LS2)

• Cadillac CTS-V (LS2)

Trucks / SUVs (Direct Replacement / Upgrade)

• 4.8L LR4

• 5.3L LM7 / L59 / L33

• 5.7L LS1

• 6.0L LQ9 (Escalade / Denali high-output)

• Some 6.0L LQ4 engines

• Silverado / Sierra 1500–2500

• Tahoe / Yukon

• Suburban

• Avalanche

• Express / Savana vans

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WHY THESE HEADS SELL FAST

• Best flowing OEM cathedral-port head

• Direct upgrade over 241, 806, 853 heads

• Used in budget turbo & cammed LS builds

• Popular swap head for 4.8/5.3 turbo builds

• Works with OEM or aftermarket LS intakes

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WHAT’S INCLUDED

• (1) Cylinder Head with rocker arms – Casting 243

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SHIPPING

• Fast UPS/FedEx shipping

• Professionally packaged

• Local pickup available