When it comes to rear sway bar mounting, ther are a bunch of choices. So, lets take a look.
1. Chevelle style, the sway bar mounts in two locations on each trailing arm. This is the least effective set-up. Unlike a Chevelle, the trailing arms are mounted solid to the axle. The combination of the axle and trailing arms is supposed to act like a big triangle and pivit/rotate around the front bushings. The designers (copiers) of this style bar obviousle failed basic geometry.
2. Bar across the bottom of the arms with links to the chassis. (as you listed from CPP) These are OK, we use them from time to time. Install is quick. Efficiency is lost the farther forward (away from the axle) they are mounted, BUT, the farther back you mount them, the more ground clearance you loose.
3. Bars mounted to the axle with links to the frame. The direct link from axle movement to frame (no suppoesed to move) is the most effective set-up. This style, like Hotchkis and Helwig, is a step up. (also like the T.A. bar) Some have the arms forward, and some go back. The back of the frame, behind the axle, usually will flex easier than the front, reducing the efficiency of the bar. Also ALL bar set-ups mentioned so far ADD to unsprung wieght. (bad)
4. Chassis mouned bars with links to the axle. This keep the axle to frame relationship, but looses the unsprung wieght. Definately the hot set-up. Mostly done with a splined torsion bar, and arms. Of coarse if front of the axle is prefered, but spring/bag clearance is tight. Cost and install difficulty are drawbacks here.
For a well built, fun driver would choose type #3, yes, #2 works and will be an improvement, and for those going for the gusto, #4. Notice the lack of #1? I knew you'd catch oc.
NEWS -- I got a look at my new project 72 last night. Not too shabby, but it does have a spiffy 80's sunroof. Oh well, easy fix. I put up picks, but it's raining today.