They were the same guns used on earlier heavy cruisers of the USN, for example the Pensacola class.
According to Navweaps, the guns were dismounted and integrated into coastal artillery instead:
http://www.navweaps.com/Weapons/WNUS_8-55_mk9.htm
The mounts on the Pensacola class were different (I think), but they had the same guns. The guns themselves were used in a shore defense battery on O'ahu.
If I remember correctly the were installed as coast defends batteries on Oahu
The gun its self was the same type used for the treaty heavy cruisers, but the mount was different. preliminary designs in the Pensacola design process used the same mount, but not the final design. The gun mounts were scrapped and the guns used for shore installations on Oahu.
Hopefully, by now OP gets the point