both classes of ships used the mark 8 gun barrels but they used different marks for the turrets, mark 1 for the county class & mark 2 for the York class.
http://www.navweaps.com/Weapons/WNBR_8-50_mk8.htm
http://www.navweaps.com/Weapons/WNBR_8-50_mk8_pics.htm