Tricked-out 747 Classics?

I have a crazy idea I want to share with you: to paint a 742 or a 743 with GE CF6-50 engines and outfit it with RR Trent 500 characteristics: 53/56 or 60k pounds of thrust in each engine, along with its fuel burn (by the way of a modified aircraft.cfg).
Anyway, it's something I thought of when I wanted to repaint aircraft.
I can say it has been re-engined with Trent 500s in the readme... do you think that kind of re-engining is possible in the real world? Or even acceptable?
Anyway, it's something I thought of when I wanted to repaint aircraft.
I can say it has been re-engined with Trent 500s in the readme... do you think that kind of re-engining is possible in the real world? Or even acceptable?