In 1963, how many years longer could a white man expect to live than a black man?

We can find data on life expectancy by gender and race for selected years between 1900 and 2007, which is issued by the United States Government. This information does not provide a figure for 1963, but we can see the figures for 1960 and extrapolate from these that the life expectancies in 1963 would not have changed very much.
According to the recorded figures, a white man born in 1963 could expect to live for 67 years. A black man, born in the same year, could expect to live for 61 years, meaning that a black man's life expectancy was about six years shorter than that of a white compatriot. The reasons for this variation pertain to differences in diet, wealth, and the types of work which were more common in the African American population than among the white population (namely, manual labor, which could lead to ill-health in later life).
https://www.cdc.gov/nchs/data/hus/2010/022.pdf