It's kind of a combo between runningart2004, and malmo, forgive me, his intolerence with this.
Want to run fast for far? Pretty simple and this is off coaches either one would respect.
Run a lot, progress your mileage, put in what is NOW known as AT type efforts, figure that one out for yourself, read the Daniels book, or don't.
For the younger guys, one thing I know to work first hand?
get your mileage up, run 1000M with 200M measured recoveries of 60-70 secs, when you can run 8 x 1000 with 60 secs recovery you will be what you are for 8K, it works almost every time