Some European Diesels have reached that amount with the same engine block and head ;-)

My dad's BWM E60 has a M47 2.0L Turbo Diesel, and with around 440,000km keeps going strong.

He probably will change it when it reach the half million due to being an old car, but the sad part here is how we won't probably be able to buy any brand new car that could reach that amount of miles without spending a lot of money on the way on repairs.