rear axle angle

It will depend on your eng/trans drive line angle. Even if someone else has a car similar to yours their engine angle may not be the same as yours so their rear end angle may not be what you need. When cars are still factory stock you can compare such things but once they are modified all bets are off that's why there are web sites like this:

http://www.moparts.org/Tech/Archive/axle/8.html

Treblig