One problem with the aggregate household income being added up is there isn't an accounting for worked hours (basically doubling the hours by having 2 people working for a company).
A different, but simple comparison would be to take minimum wage in 1968 ($1.60), adjust for inflation ($11.62 - 2017) and then compare to our current minimum wage ($7.25). So had minimum wage been tied to inflation, it would be right around $12/hr right now.