Yeah, the napa cables suck!
They don't look like the originals. The originals had wire wrapped conduit, the Napa has plastic coated.
The originals had wire only strand, the Napa has plastic coated strand. You will have to strip some plastic off of the tip of the cable where the parking brake bracket goes to for it to even fit on the end of it like it's supposed to. And they won't work right once you get them fit.
The "prongs" on the ends that snap into the backing plate are different. And are difficult to remove when you decide to **** can the parts after installing them.
Found all of this out on a set of cables for my son's Challenger.
Mancini Racing carries some from a company called "The Right Stuff" that look exactly like the originals. We're in the process of changing ours over to see how those work.
I hate to be the bearer of bad news, but it's the truth. This was my experience with Napa rear brake cables. They are the only part that I have had problems with from Napa.
I would cancel the order from Napa and reorder from Mancini, they can probably get yours to you before Tuesday. You can order the right stuff cables in sets also for around $120 - $150 for a complete set front to rear.
Good luck