Chevy 4.2 DOHC Cylinder Head CASTING# 8424S Trailblazer GMC Envoy 2002 - 2005 with Head Gasket Set & Head Bolt Kit

Machine Work Performed:

- Complete disassembly and thorough cleaning via hot tank
- Pressure tested to ensure casting is not cracked
- New valve stem seals and valve guides
- 3-angle grind valve job on all valve seats & vacuum tested to ensure perfect compression.
- PCD milled to ensure super smooth finish. (PCD stands for Polycrystalline Diamond, is best for aluminum heads).
- All parts are cleaned and inspected before final assembly to meet AERA specifications.



NO UPFRONT CORE CHARGE

CORE RETURN REQUIRED WITHIN 21 DAYS OF DELIVERY

PREPAID RETURN LABEL(S) PROVIDED

FAILURE TO RETURN CORE(S) WILL RESULT IN $500 CORE CHARGE PER CORE & COLLECTIONS FEES

**CORES MUST MATCH THE HEADS PURCHASED**

**NO CAM SEALS HAVE BEEN INSTALLED ON ANY OF OUR HEADS**



WARRANTY
ADV Cylinder Heads offers a 3 Year Unlimited Mile Warranty on all cylinder heads sold, except on High Performance heads. We ask that when installing the cylinder head make sure you are using the recommended head gasket as the manufacturer requires. You may also order the headset along with your cylinder head. Please make sure that the cooling system is in place and that the hoses, water pump, thermostat, and radiator are in GOOD working condition. Please understand that we are just selling the cylinder head and if any other part in the vehicle is old or damaged it can and will cause harm, or overheat the cylinder head. Every head sold will come with Heat Tabs which if removed will VOID your warranty. This heat tab’s center will melt if the cylinder head overheated, causing the warranty to be VOID. FAILURE TO RETURN YOUR CORE(S) WILL VOID WARRANTY. WARRANTY DOES NOT COVER ANY LABOR AND/ OR ADDITIONAL COSTS.