Stuck on calibration for (LSM303) Accelerometer

The closest I could get the Y Value was to -1 when i point it to North

Accel X: 16 Y: 52 Z: 1052
Mag X: 278 Y: -1 Z: -203

When I turn it -180 degree's (South) it goes up to -180. Is it safe to assume the Y-axis will give me my reading of North?

Accel X: -20 Y: 44 Z: 1056
Mag X: -249 Y: -180 Z: -185

Thanks!