Here is a straight comparison between all three products.
Let's call it left to right... A, B and C.
A- Rareparts.com
B- PST.com
C- OEM
A. No way in Hell these will work. Avoid them. The square bushing that come with the links don't even fit properly in the link itself even BEFORE putting them on the bar. They give you one piece bushings and will require a lot of work to get them on the bar. The clamp distorts the bushings, and looks to be for a 5/8-3/4" bar. However, looking at the shaft to base length, seems correct to the OEM.
B. Good size and is made for a 7/8" bar. Uses the same crappy solid bushing as the Rareparts unit. That's about the only drawback. I tested it with a split MOOG bushing and it was perfect. Clamped down tight and did not kill the bushing too much. The shaft to base length is noticeably shorter, not sure what effect that will have on the bar, if any at all. The material and assembly of the links seems to be OEM quality, despite the difference in the design. The bottom is rounded, so it clamps the bar real well, without distorting the bushing. Bolt provided is a fine threaded bolt, which is good, for this application, but I'm most likely changing it over to a SS set anyway.
C. OEM... well.. if all else fails and you don't want to go for the $100 for the two PST links, it a cutting and drilling bonanza for you. It really doesn't look too hard to do this, but for the time and aggravation you'll spend on cutting it and opening it, you might be better off spending the $$$ but that's your choice.
Either way... get the MOOG bushings for the bar. They are far better than the bushings either of these companies give you with their links. They seem hard and made with less quality rubber. The provided upper bush sets are larger than the MOOG set, I have to see how that effects the mounting in the bracket. I will test both sets once I get it on the car. I will say this, and you can see it on the (A) product, the bushing caps are crap on both. MOOG gives you near OEM thickness of their caps. In honesty, I really prefer the MOOG products as I have used them extensively everywhere on my lifted '99 Cherokee and have had NO issues whatsoever in almost 6 years since I've completed that vehicle... and it's my DD 35 miles each way on the Southern State Parkway.
You decide which direction to go, I just thought this little bit of info on these things will help someone down the road.
Here are the three units... again... left to right A (Rareparts,com), B (PST), and C (OEM) next to a MOOG bushing.
JR