@habibalam... Buddy efi cng kit was already install in it when my baba bought it 2years back.
Those who say cng on 660 is not good then i guss then shud stick with petrol. Bit let me tell u all that k using my 660(manual) on daily run in city and m completly satisfied ! With and without Ac, and dear ofcrz Engine will take load on Ac, bhai 660 hai koi jahaaz to nae k power drop nah kry. Pakistani alto say bhttt comfortable nd i just love it.