It could have a 7k steering axle and a 17k driver which would give a gvw of 24,000. Are you sure that it uses 10 lug bolts in front or do the wheels just have 10 holes with a bolt in every other one? I'm not sure if a 50 series with offered with 10 hole stud piloted, but that doesn't mean that someone didn't change components in the last 40 years.
