Be careful with what steak said. The van could lunge forward when you put it in gear with the engine rev'ed if the torque converter is locked.
If the van is facing a wall and if nothing is behind, I would put it in reverse. But also another caution, if you do put it in reverse, know that if it lunges backward it could cause you to increase the throttle without meaning to.
'03 Dodge Ram 1ton, Cummins diesel, 6 speed manual, 4x4, SRW, quad cab, short box
'04 Town & Country mini van, 3.3 v-6, no ABS