2009 supercharged 6.2L V8 engines use a keyway to locate the balancer, and the timing sprocket and balancer must be installed over this keyway
J-41665-A is slotted to fit over this keyway, and is used with the forcing screw and hardware from either J-41478 Front Seal Installer or EN-47812 Front Seal Installer Bolt to seat the lower timing gear sprocket and then the engine balancer
Both are press-fit, and must be fully seated to prevent damage to other engine components, such as the oil pump
J-41665-A will back-service all small-block V8 engines to 1997 (4.8L, 5.3L, 5.7L, 6.0L, 7.0L), with or without the keyed balancer