Dear brother, these engines are sourced from abroad. They're basically coming from dubai scrap yard, Japan scraps and from scrap yards of other countries..
So mighty J is from Singapore, Japan etc.
5,7a's also from abroad...
As we know, in the countries mentioned above these engines & cars were scrapped long back. But the engines which are removed are mostly less used and are in good condition.. So this is the channel by which they're still available here in our markets..
Different countries have different type of scrap. Like Hong Kong, Singapore, Phillips, Trinidad and tobbago such countries have cheap old engines mostly and Japan, Europe has mostly new engines since there laws don't allow old gen engines. So the scrap coming from such countries is kinda new like m series, nz series etc.