1985 Pontiac Firebird Brakes grinding

Alright I bought an 85 firebird and the breaks were shaky so I went ahead and changed the brakes and rotors. The change was very easy as far as that goes. But now I am getting a really bad grinding we checked the wheel baerings and that wasnt the issue. It seems the grinding is comeing from the brake pads. We thought they just needed to be worn down, yet the ginding will not stop the brakes grind while moving and squeak when turning. I was just looking for anyone who may have any suggestions. Allright thanks for your help.