1975.
Your serial number indicates that your Glenfield model 60 was made in the year 1974.
1975.
1971
1970
your glenfield was made in 1968.
With the serial number that you have provided,your Glenfield model 30A was made in the year 1977.
Your serial number indicates that your Glenfield model 20 bolt action was made in the year 1980.
1968
1980.
that would be a 1974 model
1967
1978