Don't know precisely, but lets work it out!
Let's assume standard arms are X cm long and that on a normal height vehicle they are horizontal.
If you lift it by 2", you have a right angle triangle (roughly) with one side 5cm, one side X cm, so by pythagorus, your new length Y will be:
Y = Square root ((5 x 5) + (X x X))
The bend will not be absolutly at the chassis end (probably 10cm away towards the axle or so). Lets call this distance away from the chassis mount Z.
The angle of the bend A will be:
Tan A = 5/(X - Z)
or
A = ArcTan(5/(X-Z)) degrees
If you measure the length of your existing arms, from the middle of the chassis bush to the middle of the axle bush (the two points around which it rotates), I or someone else will calculate it for you if you like.
Si