does the 1970 census count ged recipients as high school graduates
The 1980 Census form was the first to explicitly state that earning a GED was equivalent to completing the 12th grade. In 1970, it is likely that respondents who had received their GED would have instead reported their last year of attendance in the traditional school system as their highest grade attended.
You can see how this question was asked as well as the instructions provided to enumerators on this page.
I hope this helps.