---tab Description--- Description Restore performance and reliability to your aging Duramax. The SPELAB All-Aluminum Tube-Fin Intercooler is the ultimate durability replacement for the 2001-2005 Chevy/GMC 2500HD/3500HD (LB7 & LLY). Older Duramax trucks, especially the LLY, struggle with engine coolant overheating when the cooling stack is restricted. Unlike thick, heavy aftermarket cores that can block airflow to the radiator, SPELAB's 40mm Slim-Profile Tube-Fin core is engineered to maintain factory-level airflow pass-through. This design prioritizes the health of your entire cooling system, keeping water temperatures safe while towing. Crucially, this unit replaces the failure-prone factory plastic end tanks with 100% aluminum. No more blown crimps, no more boost leaks—just reliable, consistent performance for your work truck or daily driver. Fitment 2001-2005 LLY LB7 Chevrolet/GMC Sierra 2500HD 3500HD 6.6L Duramax Key Features Radiator-Friendly "Slim" DesignThe Duramax LLY is notorious for overheating while towing. Installing an overly thick intercooler often makes this problem worse by blocking the radiator. Our 40mm Tube-Fin core is designed to be "transparent" to airflow, ensuring your engine fan and radiator get the cool air they need to prevent coolant temperature spikes. Permanent Leak FixThe stock intercooler uses plastic tanks crimped to the core, which weaken and leak over 20+ years of service. Boost leaks cause high EGTs and power loss. The SPELAB unit features solid aluminum end tanks welded to the core, providing a leak-proof seal that will outlast the truck. Fast Heat SheddingTube-Fin construction excels at shedding heat quickly. In stop-and-go traffic or variable load driving, this core recovers from heat soak much faster than heavy bar-and-plate units, keeping your intake temps consistent. Direct Fit RestorationDesigned as a direct drop-in replacement. It fits perfectly in the stock location without modification, making it the ideal choice for truck owners looking to refresh their aging cooling system with upgraded materials. Specifications Core Thickness (Tube-Fin) 40 mm Material Full aluminum alloy Weight 12.76 kg (28.1 lbs) Package Dimensions 120.5 × 25.5 × 66 cm (47.4" × 10.0" × 25.9") Installation Direct Bolt-On ---tab FAQ--- Q: Why is the core 40mm thick?A: We maintained a slim profile to ensure maximum airflow reaches the radiator. This is crucial for the 2001-2005 Duramax trucks, which are prone to running hot if the cooling stack is obstructed by a thick aftermarket intercooler. Q: Will this fix my boost leak?A: If your leak is coming from the factory plastic end tanks (a very common issue), yes. Our all-aluminum welded design permanently eliminates the risk of tank separation. Q: Is this an upgrade over stock?A: Yes, in terms of Reliability. While it flows similarly to stock, the switch from plastic-crimped to welded aluminum makes it significantly more durable and capable of holding boost pressure without leaking. Q:...