Drive Shaft Angles - Harmonics and Vibration
--WORK IN PROGRESS--
This is a DIY, need to fill out the discussion on why each is bad, but you can start with the `EZ Read` diagram below.
Hang on for more information on this, as it's pretty simple, but sometimes hard to figure out the angles without a few simple tools. I did this for the Sunbeam Tiger axle swap and used a digital protractor that really made things easier.
In some cases you can fix issues with angled shims in the rear end or adjust suspension links to get things where you want them. Drag race cars need to be set up different than road race and again off road vehicles. But seems like the basic ideas hold for all.