@mr_malik2
Keep this thing out of your mind that the new kabli engine will not run...it will run forever if you know about it.
Second thing, GA15DE is better than DS. There is not such a wiring mess and CNG use to give 170-180 on highways and 120 in city for sure in city and i am talking about Lahore cng, which is the cheapest in quality among all the country.
Thirdly, I advice you to check your engine properly why it is reducing oil, there are many reasons for it, if it comes up that you have change the head, then you should go for a complete swap with GA15DE, which is 105 hp engine.
I also own a B13 and just swapped GA15DE four months back and quite satisfied with it, maybe it has crossed the 10,000 km figure without any problem.
@SER_GTR
Bhai i need your number :), please do send me your number at 0321-4748787. I will be waiting. Also, please tell me which AC compressor you are using ???