Yes, 400 k is not a problem - Engine, Tranny, Diffy all solid if well maintained.
The problem would be with the rest of the car. As you can see, a lot of parts wear out over 10 years.
We need a test driver to put 100K a year on a 2000 or so LS - Then we would have a car with 500K+ miles and no work on the suspension, mounts, PS, ets. :D