Re Il-76 - not overloaded. There was commentary on a thread about this, and if I recall correctly it's a technique used to comply with segment requirements after lift off. Think mention was made of the early 707 using the same. Will search for the relevant thread.
See here, in particular post #75. Other relevant posts #104, 120, 140
http://www.pprune.org/rumours-news/3...red-video.html