Hi i am replacing my head gaskets on my 2000 grand am gt. After getting the heads off and cleaning them i went about checking them for warpage. I used a 3ft level and a piece of paper. I checked corner to corner and vertical and horizonal on the head. The piece of paper went under the level but barely not all the way. I was wondering if there is a tolerance that u can have that the gasket will fill or should i just have them redone? I am trying to do this as cheap as possible. Any advice will help thanks