Internals + BDT + BBT + Slipper + IFR pod
The IFR Pod held slightly less fuel than an UWT but with Internals + BDT + BBT + 2 UWT (slippers) you would have 23,000lbs or 2300 nms at 35,000ft! Enough fuel to go a very long way and certainly across the Atlantic (Azores to Gander; done it) and even island hopping across the Pacific (inc. Hawaii to San Francisco; planned it but it was never flown).
The problem with the BDT and the cat would have been that you could not get the angle of attack required on the cat because the BDT would have been in contact with the flight deck at launch!
Foldie
