This Google Earth image shows the remarked stands, although the 767 image has been superimposed for reasons which only Google can answer (it appears on their historical images as well, going back as far as 1945
). Stand 42 is the normal spot for the 767-300 (180ft 5ins long), stand 42R is left of 42 in the picture with the forward stop bar and was intended for 777-200's (209ft 1ins long). There was an unsubstantiated rumour it wasn't long enough and, as LTNman says, El Al haven't sent us a 777 since October, although IIRC the stands were already marked before then. As for the 787-8 (length 186ft 1in), I don't believe it has been parked on a terminal contact stand yet and the only commercial flights I know of so far have been parked on the south apron. Wingspan shouldn't be an issue, 2ft 8ins less then the 777-200.
As for Air India operating Amritsar-Luton, well, the statement quoting Luton as the London airport due to a lack of slots at Heathrow seems to have come from a minister of some kind whose knowledge of aircraft performance from short runways, not to mention the suitability of the planned destination airport, is probably nil. Dream on.