Originally Posted by
Icare9
You'll find an answer by using Google to search
To make it "easier" for you, Wiki has
The last B.2 XM657 was delivered in 1965 and the type served till 1984. Whilst in service the B.2 was continuously updated with modifications including rapid engine starting, bomb-bay fuel tanks, wing strengthening to give the fatigue life to enable the aircraft to fly at low level (a tactic introduced in the mid-1960s), upgraded navigation equipment, terrain following radar (TFR), standardisation on a common nuclear weapon (WE.117) and improved ECM equipment.[49] The B.1As were not strengthened, thus all were withdrawn by 1968.[50] Nine B.2s were modified for a maritime radar reconnaissance (MRR) role[51] and six for an airborne tanker role.[52] An updated bomb rack assembly allowed the carriage of 30 1,000lb bombs, up from 21[53] and the updated wing profile increased range to 4,000nm (7,400km).[54]
Never heard of the 30x1000lb mod? When did that come in? Could wiki be wrong?