Angled Shocks

Mounting them at an angle lets you fit a longer shock into
the same vertical distance.  Longer shocks will obviously
give you more travel (assuming that your springs are also
long enough, etc).  Mounting them at an angle also reduces
the ratio of shock movement to vertical axle movement.  If
your shock was 10" long, mounted straight up and down, 1" of
vertical movement of your axle will result in 1" of shock
travel.  With the shock at a 45 deg angle, 1" of vertical
axle movement results in .689" of shock travel.
Since an angled shock travels less for the same vertical
distance, it is also required that you use a shock with more
damping.  Using adjustable shocks like RS9000s is a good
idea.

As far as angling the shocks in towards each other, many
people say that it helps reduce sway.  I've thought about
this a lot and I don't see how it can.  By mounting the top
end of the shocks to a point in the center of the frame (ie:
dead center between the frame rails) you are choosing a
point which moves very little when the chassis is swaying
back and forth.  Remember that vehicle sway generally
involves the chassis rolling about its axis.  The closer to
the axis you mount the shocks, the less movement they will
see.  To control sway, you are better off mounting the
shocks further away from the axis.  In most cases, this
means mounting them to the frame rails.  So how do you run
longer shocks AND mount them to the widest points of the
frame and axle housings?  You angle the shocks FORWARD or
BACKWARD.  This gives you roll or sway control and allows
you to run longer shocks, as well.

- lars