Blitzology posted links to some playbooks for people interested in the 4-2-5 defense.
Also, I have included links to two other files.
First, is a link to a 1997 article by Gary Patterson describing some of the principals and philosophy behind the 4-2-5. If you have not read it, it is a short but worthwhile article on the ideas and benifits that are behind the 4-2-5.
Second, is a link to an AFCA article by David Baliff, the current head coach at Rice University. He is the former D-line coach for TCU and Head Coach at Texas State University (formerly Southwest Texas State). He currently runs and has run a very similar scheme to Patterson's. This article details some blitz and alignment principals.
Third, is another article by Baliff where he outline some technique and schemes with d-line twists. The information on technique is excellent as well as the simplicity behind the twist game terminology, this is typical wording to anyone familiar with the 4-2-5.