PPS,
I think, without even looking, that all the space behind the bit where the driver sits is probably packed full of intake trunking and two engines, mot to mention ancilliary stuff and possibly black majic boxes of one sort or another. If there was anyplace at all to put a fuel tank in there I think Northrop would have discovered it a long, long time ago and actually put one in there.
Pull the other one.
Doc C