GMC 1993 Safari Owner's Manual page 195

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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If there is no curb when you're parking uphill, turn the wheels to the right.
If there is no curb when you're parking uphill on the left side of a one-way
street, your wheels should be turned to the left.
Torque Lock (Automatic TriWsmission)
If you are parking on a hill and you don't shift your transmission into P
(Park) properly, the weight of the vehicle may put too much force on the
parking pawl in the transmission. You may find it difficult to pull the shift lever
out of P (Park). This is called torque lock.
To prevent torque lock, always be
sure to shift into P (Park) properly before you leave the driver's seat. To find
out how, see "Shifting Into P (Park) in the Index."
When you are ready to drive, move the shift lever out of P (Park) BEFORE
you release the parking brake.
If "torque lock" does occur, you may need to have another vehicle push
yours a little uphill to take some of the pressure from the transmission, so
you can pull the shift lever out of P (Park).
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