depending on how wide the stage is you may have to go beyond 90 degrees
...and do not be afraid to split them and throw out traditional stereo pair techiniques if the stage plot calls for it. For instance, if the drums are centered and loud, while the amps are not very loud and concentrated on the wings of the stage, you'll be much better off splitting the mics vs. running a traditional stereo pair DFC on the stage lip.
Most of my stage sources these days are the 414s split and using the wide-cardioid pattern, however, I also like doing split card set-ups with SD mics and then will often point them in at the drums a bit.
Plan, however, that you will get hosed on the vocals for any stage mic set-up. Even if you get a good shot from the monitors, the vocals generally sound crappy out of monitors vs. a PA recoding or a SBD feed. Stage micing is not generally appropriate for a band with vocals unless you also have a room/PA source or the SBD feed to make a matrix.