While we already know that probe and drouge refuelling will be possible using the wingtip tanks, will there be a centerline feed as well like on the KC-10, or will it have to be installed before flight like on the KC-135?
"Example: Though USAF wanted plumbing in the wings for wingtip probe-and-drogue refueling, to lower cost, it dropped the requirement. The aircraft will have both a boom-type refueling system and a probe-and-drogue, both on the centerline."
South Carolina - too small to be its own country, too big to be a mental asylum.
It's not like you could fit more fuel in a -300, and the additional cargo capacity (volume, rather) would not make much of a difference either. Basically, you would have an airplane carrying a bunch of extra weight around for decades, not good for the fuel budget. -200ER seems perfect for military (tanker and otherwise) applications, especially seeing as it's the 767 with the greatest range.