I am not sure but try searching for Universal radiator (desi name for a desi radiator) for your mehran. My driver told me about it. According to him its bigger in size, it has two fans so, it should be able to cool down your mehran.
Another thing he was telling me was about universal condenser for ac. It is suppose to work far better than orignal one.
Do check with someone who has done this with their mehran.