Like the title says, I'm going to be replacing my harmonic balancer this weekend (finally). So, I'm going to have to pull the main bolt out of the crank to complete the operation. Now, I know sometimes the threads on the main bolts are backwards from normal, so lefty=tighty. Does they Chevy 350 from '91 have regular threads, or backwards threads. I have no interest in going the wrong direction, considering I don't have an impact wrench to get the bolt off, and my father has in the past broken a main bolt... Thanks for the help.