From what I have read yes you need to replace the stock RCA components before putting on the new rear bar. Ths stock RCAs are pretty much useless and need to have beefier replacements.I am making the final decision very soon on what combination I want to go with.
As for the rear control arms : they are flimsy pieces of pot metal. The STOCK rear swaybar is stressing them pretty good. Bigger rear bars are stressing them to the point that total failure of the arm (usually the bar mounting bolts enlarging the holes in the arms, leading to cracks and/or the bolts coming thru the holes) is a very real concern.
I have the Global West lowers now (spherical front bushings, del-a-lum rears) : best arms on the market (IMHO). The spherical bushings in them are starting to loosen up slightly and make a little rattling noise (after 15K or so miles) but it's very livable.
Before that, I had the Hotchkis lowers. They also worked fine, and are a HUGE upgrade over stock (regardless of the rear swaybar issue). As long as you keep them well lubed, the Hotchkis arms are QUIETER than stock (bushings are silent, and no creaking/popping like I occasionally got with stock lower).
The lower arm offerings from J&M, Metco, and BMR are also nice. I'd have no problem putting ANY of them on a car that I was gonna drive...HARD. "Bang for the Buck" champ right now is the BMR arms.
As for the uppers, I still have stock uppers (with 96K fairly hard miles on them)....they are getting a bit worn on the bushings, but otherwise are fine. I'll eventually swap them (have a set of Metco adjustables sitting in the garage), but it's not a mustdorightnowtomakecardrivable kinda thing
You will have to use the brackets that come with the Hellwig and you might want to pick up some new swaybar endlinks(F-body ones). Just remember DO NOT re-use the stock bolts on the front swaybar brackets. I've been running the Hellwig bar up front with the HO bar and BMR LCAs in back for a while and am very pleased/impressed with this combo.
You can use their endlinks, but it seems that the sleeves are too long, try to use your stock sleeves from your old endlinks. Man what a difference in the Hellwig sway bar and the F-Body; its feels much tighter and from my opions seems to raise the front end a little.
Save mucho $$$$$$$. You don't have to spend a wad of cash on some fancy afftermarket rear control arms. You can box the factory ones in by welding some flat steel into the open bottoms, and they sell some kits that already have cut-to-fit pieces that u, or a welding shop can just weld right into your factory arms. I have done it to mine, and they hold up just great, and made a hella difference. A dissasembly is needed, but you'd have to anyway for the aftermarket ones. It took me bout and hour remove all four of the control arms, of course I have all the right tools, and power tools too though. Also, this is the best time to replace the bushings with some polyurethane ones, and u might as well buy a whole car kit if you have'nt done the front yet, because its cheaper if you plan putting some poly in the front A-arms sooner or later. Here is the facts, you can buy an entire poly kit for your can, and box in the factory control arms for a lot less $ than just buying them fancy arms will cost ya, and after boxing in the arms, and replacing all the stock bushing with new poly ones, you will of had made a bigger handleing improvement for less $$ than just putting them fancy, high dollar arms gona cost. There is several kinda fancy arms u can buy, and the only ones that would might be better than what I suggest doing, are the ones that allow u to adjust pinion angle, but really they are not nesecary unless you are a hard core drag racer, and every ohter source of traction has been maxed.
True--you can box your existing control arms in the method you described. This is an ok way to get a little better performance out of the OEM pieces. It is, however, a poor man's mod and boxed control arms are nowhere near as rigid as aftermarket units made out of much thicker material. Not only that, but I doubt they'd hold up to the stresses a large rear sway bar like the HA/HO puts on the lower control arms. Ed Runnion knows a lot about this, and he also has pointed out that the rear control arms are made out of such flimsy material that the heavier sway bar will just tear them apart.
Boxing them may make them somewhat more rigid for normal use, but with the aftermarket sway bar they're destined to fail--sooner or later--and I sure don't want to be in the car with you when they do.
<BLOCKQUOTE>quote:</font><HR>Is the Hellwig Bar better than the F-Body?<HR></BLOCKQUOTE>
Depends on what kind of configuration you're going for. But now I can't remember for some reason. I think a stiffer front bar will push the neutrality more towards understeer--which will cause the vehicle to plow through a severe turn rather than have the end swing out. (Someone please correct me if I've confused this again.) IMO this is good for the street--If you've ever had the rear end of the beast swing out unexpectedly, you know what I'm talking about. Of course shocks, springs, and more all have an effect also.
Looking Into getting a whole new suspension kit for 96 impala. Had for about 10 years now just sitting, so like to bring her back to life with a while new upgrade rear and front suspension including shocks/struts. Just put a new battery, fresh Royal purple oil, k&n oil filter, and k&n air...
I'm working on a project that has B-body frame clips. I installed the Hotchkis Impala SS springs, but it's REALLY low in the front. I had a set of SS springs, but sold them to a local member. Now I'm thinking I need something more along the lines of the Global West springs (closer to stock SS...