Identify factory sway bar piece?

The way that bar is shown suggests it is a aftermarket bar for a Chry' product. Fits the perimiter of the K nicely.
As for answering your width question... The staock bars and aftermarket bars are all different widthed due to where they attach.
Correct 67 to 72 bar widest as it attaches out toward the lower ball joint.
73 up bar looses about 6 inches of overall width as it attaches near center of lower arms.
Most aftermarket bars attach at lower shock bolts so overall would be even shorter.

Lets call that an Addco bar. Mount it out in front of the balancer and attach the linked ends wherever they land.