Tim, if it was long enough to land on at normal landing weights it was long enough to take-off from.
6000 ft was the normal minimum landing supposedly with a TBC stream. As I recall El Adem was only 6000 or 6500 feet in those days and we could never stream because of cross winds
Chivenor and Brawdy were both used regularly and were about 6000 feet with many others at only 7000.