767-X is basically a 767-400ER with taller landing gear and GEnx engines.

It’d make a fantastic MD11 replacement for UPS/FDX, and with shorter wings, fit on more passenger gates than a 330 CEO.

One issue is Boeing was only making 2.5 767/mo with a sizable order book from USAF, FDX and UPS. Boeing increased production to 3 airframes/mo this month but that’d likely need to come up substantially to support new passenger orders.