I was looking over the specifications of the different V-Bombers operated by the UK and I came across a mention of the Vickers Valiant B.2.
By Wikipedia and the other sources I found it was optimized for a low level strike. Stronger and larger airframe, heavier landing gear and faster on the deck than the production version. Of course it was cancelled because in 1955 it hadn't yet sunk in that high altitude bombing wasn't going to last well as an idea and the pathfinder mission it had been specifically built for was considered outdated.
Intrigued by this I checked the range of a standard Valiant B.1, it's listed as 4500 miles unrefueled. The Vulcan's range was only 2600.
The extra fuselage length in the Valiant B.2 probably didn't hold more fuel, but it has a pretty good range already, and with those Avon engines it could have been re-engined down the line for better fuel economy with relative ease (even with newer versions of the Avon itself).
*** I checked, a good replacement engine down the line might have been a non afterburning version of the Turbo-Union RB199 used in the Tornado. Similar size, better thrust (in later versions), can't say if the fuel consumption is better 'cause I can't find a figure to match with the Avon! Also to be considered are the Spey and the EJ200 (the Brits would probably stick with a Brit engine for political reasons if nothing else).
What if something changed the minds in the RAF about low vs high altitude missions in the mid 50's, considering the size of the UK bomber force in the Cold War and the size of their opponent a change in tactics to improve the chances of the bomber is not anywhere near ASB (I think). The evidence was starting to mount that high altitude wasn't going to work much longer.
They could also see the Valiant B.2 as being on the same page as the USAF/SAC B-52... a bit more ASB I admit.
Where am I going with this you ask? The BLACK BUCK raids!
Imagine if the bombers used in BLACK BUCK were coming in on the deck and had much better range (the mission was ~4000 miles each way), maybe even drop tanks (the B.1 had provisions for underwing tanks), maybe those wing hardpoints instead of fuel carried standoff missiles?
If the Vickers Valiant B.2 (upgraded to B.4 by the 80's?) had gone forward as the main bomber of the V-force and existed in improved forms to this day what impact would that have had in the British involvement in NATO, the Falklands War and even today in Iraq and Afghanistan? Could the Vickers Valiant B.2 become the UKs counterpart to the B-52?
UPDATE:
Found some pictures of the B.2 at this link:
http://www.aviastar.org/gallery/valiant.html