I'm going with the QPR fans from when we were talking about the Leeds game. At the time they were saying they thought the away end as a whole held 3,100 (with 200 lost to blankets if home fans are in the lower tier) and that it was an 1,800/1,300 split.
Leeds were then given about 1,800
http://www.leedsunited.com/news/20110407/qpr-important-ticket-information_2247585_2332980
EDIT: QPR OWS says it takes just under 3,400. Upper tier holds 1,723, plus if required the lower tier is opened and holds 1,417 (with 116 restricted view in the upper and the front rows of the lower availlable only with the safety officer's consent)