Ordered a TJ/LJ/XJ/ZJ long arm kit, and one upper arm is straight and one is bent?

The straight upper control arm is used on the passenger side. The bent or angled one is used on the driver side. The angle is done for additional clearance for a high pinion axle. It may not make a difference on a D30 but with a HP D44 and HP D60 this angle make a difference.