@abdullah53 you can go to Jamshed Road from Jail Chorangi side, there will be Total patrol pump on left side, turn into street just beside this patrol pump, there's Raja Autos, 2nd shop I guess.
Ask for Ishaq Ustad. I've got my 1995 Mini's manual gear fixed from him. He have experience with Pajero Minis.
If you go to Sher Shah yourself, you can bargain a deal. Maybe 4k-5k for turbo of 660cc. Or you can ask Ishaq to get one for you. It will be a bit pricier.
Best regards.