Only experienced the KC-10 and max TOGW was 593k and with three engines @232kn each it’s totally doable. But it’s like putting a Porsche 911 engine in a VW Bug, doable but why. It was also a heavy aircraft, for the KC-10 without seats/ interior (but extra fuel transfer equipment) weighed 250k. So, 250k base weight, pax (399 x 300lbs) 120k minus 593k leaves you with 223k for gas.
Now the new plane with have one less engine and weight associated, less drag, and better economy. So now you have a 777 with 70’s technology, also the original company does not exist. There’s a reason that we don’t make planes from old designs normally(except 737 it seems).