This should be simple, but looking at the two parts I can't tell what the difference is. I looked at my master cylinder and I see two brakes lines come out. One goes in and out of a thing that looks like a tiny ABS unit. A function that I've actually never been able to get to work. So my assumption was that it was a 2 wheel unit. Well, the weather sucks anyways, but I stopped by Advance auto just to look. Crazy expensive there so I'll order from Rock Auto. The problem is that the parts look the same, so I'm not sure why it's like a $40 difference.

Rock Auto is only a $3 difference.
2 wheel hub
Moog 515072

4 wheel hub
Moog 515073

So like I said, just for sanity I need some confirmation that this is a 2 wheel ABS system. I wouldn't put this much thought into it if returning parts was easier.

 

If you don't know for sure, you can pull your wheel off. If it has 4 wheel ABS there will be an electrical connector on the front hubs. No connector, no front ABS.

Or go pull your build sheet from the online system at Dodge's website.

http://www.dodge.com/webselfservice/dodge/index.html

Hit the equipment listing button on the left, and drop in your vin. Instant build sheet.

 

Thanks, I forgot about the build sheet. Looks like just the 2 wheel option for me.
"4 Wheel Disc Rr Anti-Lock Brakes"

 

Yep, same as my sheet, just rear ABS on my truck as well.