Swaybar work should be done with the truck on the ground.
Make sure it's sitting level. Then loosen the brackets mounting it to the frame just enough you can turn the bar. Insert the end links,washers/bushings/etc. Tighten down, and then tighten down the frame brackets.
Don't torque em too much, I'm running off memory but I think it was somewhere in the 25-50 lbs/ft range.
Make sure you have the bushings and washers in the right position/orientation. It should be (from top to bottom with nut on bottom):
Bolt Head
Washer
Bushing
Swaybar
Bushing
Washer
Metal bushing
Washer
bushing
Lower A arm
Bushing
Washer
Nut
