Advanced Flow engineering (aFe Power) introduced cold side intercooler tube upgrades for the 2001-2005 GM Duramax LLY/LB7 with the V8-6.6L (it) motor part number 46-20048. Constructed of huge, mandrel bent 3-inch 409 stainless steel, the tube is powder-coated for maximum cooling efficiency. Two heavy-duty, five-ply aramind reinforced couplings give the upgrade strength to withstand high boost pressures. The system includes two 1/8-inch NPT bung for gauges and other performance inputs. In testing, the 46-20048 outflowed the factory intercooler tube by 40 percent.
Duramax intercooler tube