I use:
Code:
    DEFINE  ADC_BITS        10  ' Set resolution of conversion
    DEFINE  ADC_CLOCK       8   ' Set clock source (x/FOSC or FRC)
    DEFINE  ADC_SAMPLEUS    50  ' Set sampling time (in uS)
However as I recall you have to switch the ADRESH/ADRESL to right justification for 10-bit and left justification for 8-bit.