Fuxk the factory crap, go with an ARP and a lot of red locktite torqued to spec and it'll never come off. I had a 150 shot on my ls2 and after I pinned the crank I never had a problem with the balancer coming off or bolt backing out. The only reason the bolt spins loose on a stock setup is cause the pulley spins on the crank and loosens the bolt. If the pin and an ARP will hold a shot of nitrous and the instant torque that it makes, it'll deff hold the gradual power increase of an NA or blower car.