Finding your driveline angle is the easy part; deciding what angles work best for you, however, can be a challenge. Please review the following video for a demonstration of driveline angle affect.
Driveline Angle Affect.
Simply put, an incorrect driveline angle can create vibration, cause premature universal joint failure, and reduces power to the rear wheels. Consider the following article from hotrod.com.
How To Set Pinion Angle.
Tremec has created a free app for smart phones that measures the driveline angles and displays whether they are within specification. Below is a link to a PDF of the app’s instructions as well as a link where the app can downloaded.