GMC 2013 Savana Owner's Manual page 318

4. Position the jack under the
vehicle, as shown.
The front position jacking point is
on the frame. The rear position
jacking point is on the rear axle.
If the exhaust system interferes
with the jack location in the rear
axle, such as in Diesel vehicles,
place the jack (1) on the rear
axle between the axle housing
and the shock absorber bracket
in order to avoid any
interference with the exhaust
pipe (2).
Getting under a vehicle when it is
jacked up is dangerous. If the
vehicle slips off the jack you could
be badly injured or killed. Never
get under a vehicle when it is
supported only by a jack.