So here's my situation. I have a set of hair pins my uncle had made back in the last 60's for his hot rod but never did so recently he gave them to me. He had already drilled and tapped the bat wing ends for 1/2 20 heims or whatever he planned to use. I got to looking around notice most people use 5/8th for a good reason. I was more or less just curious with if 1/2 would be strong enough. Their rated for over 7,000 lbs. each which seems like a lot, kind of. Its going to be in a open wheeled car with a Y block. Comments and opinions would be appreciated, especially if you have known experience.