Malcrf, the Vulcan, with a teeny seen t was able to add two drum tanks to Iranian bay.
Strip out the NBS and ECM and make the bays wet, pod weapons and ECM under the wings like the B58, put an extra tank in the bomb bay and you have a serious amount of extra fuel.
Then replace 4 oil burners with two reheated burners and you would have a much greater unrefuelled endurance.