GMC 1999 Sierra 1500 Pickup Owner's Manual page 228

Your Driving and the Road
You don't have to jam your tires against the curb, if there is a curb. A gentle
contact is all you need.
Parking Uphill
I
If there is a curb, turn your wheels
to the left if the curb is at the right side
of your vehicle.
1
AM470045
If you're going uphill on a one-way street and you're parking on the left side,
your wheels should point to the right.
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