I would imagine the aftermarket might build in a small amount of oversize since they know this is going in 50 year old stuff most likely. Maybe?

I haven't used pro forged on my Barracuda yet but I bought them for my Jeep a few years ago. So far the ball joints from them have out lasted the moog stuff subtantially! My jeep has oversized tires and ball joints are kind of regular service, the pro forged stuff is hanging in way better.