GM-41665-A is used with the draw bolt and nut from tool GM-41478. If you want to buy just the bolt and nut, the part numbers are 280055 and 90592A034 . When used on LS7 engines, GM-47812 is required instead of 280055

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. GM-41665-A is slotted to fit over this keyway, and is used with the forcing screw and hardware from either GM-41478 Front Seal Installer or GM-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. GM-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.