If I remember history correctly, left handed threads on the driver's side of vehicles can trace it's beginnings to horse drawn wagon days. The direction of travel would prevent the hubs from loosening up. That was the standard through the early sixties, on some vehicles. Years ago, I started a collection of left handed lug nuts. There is no way to tell them apart without examining the threads. At least the studs have an L on the end of them. Both my wagon and CJ2A have mixed and matched studs on the left side. Each stud has to be looked at, when removing a wheel. What a pain in the rear. When I get the notion, I will change them all out. Now with that being said, will I change the left side to left handed thread? Depends on my mood. I doubt there are too many wheel thieves, that are out looking for steel Jeep wheels.