2001-2004 Duramax Reman Stock Bosch Injectors W/Install Kit (412603)

The 412603 is the complete LB7 Duramax injector replacement package — 8 Bosch reman stock injectors plus the full install kit (valve cover gaskets, GM high-pressure fuel lines, O-rings, banjo washers, return line bolts, and Mahle silicone sealant) for the 2001-2004 6.6L LB7. The LB7 is notorious for injector failure — the injectors live under the valve covers, drip fuel into the crankcase as they fail, and almost always need to be replaced as a complete set of 8. This kit puts everything you need into one box so you don't end up halfway through the job missing a $4 gasket.

Each injector is built from a genuine Bosch core, fully disassembled, and rebuilt with brand-new internals — not just refurbished old parts. Industrial Injection balances each injector to a tighter flow tolerance than factory OEM, which addresses the LB7's known issue of balance-rate drift between cylinders. Every finished injector is run on a Bosch OEM test stand before it leaves the line.

This is a heavy job — the valve covers, fuel rails, and intake hard parts all come off to access the injectors. Plan a full day in the shop, and don't start until you have all 8 injectors plus the install kit on hand.

• Complete Kit — 8 Bosch Reman Stock Injectors + Full LB7 Install Kit
• Direct OE Replacement for 2001-2004 6.6L LB7 Duramax
• Includes 2 Lower Valve Cover Gaskets
• Includes 8 GM High-Pressure Fuel Lines
• Includes 24 Lower Valve Cover Grommets + Upper Radiator Pipe Seal
• Includes 8 Injector Body O-Rings, 8 Copper Crush Washers, 8 Return Line Banjo Washers + Bolts
• Includes 2 Return Line Banjo Washers + 2 FICM Line Banjo Washers
• Includes Mahle Silicone Sealant for Valve Cover Reseal
• Brand-New Bosch Internals — Not Just Refurbished Cores
• Balanced Tighter Than Factory OEM Tolerance
• $870 Core Charge — Fully Refundable Within 45 Days of Return
• 2-Year Unlimited Mileage Warranty

• LB7 injectors live under the valve covers — plan on pulling intake hardware, removing valve covers, and reinstalling with the gaskets included in this kit. Plan a full day in the shop.
• Replace all 8 injectors at once. The LB7's high-pressure fuel system is balanced across all 8; mixing new and old injectors leads to immediate balance-rate codes and uneven idle.
• Cores must be returned within 45 days for the $870 core charge to be refunded. Late returns forfeit the core deposit.