I know this is around a year old but may still be of great interest here...
Here's my thread from the Crossfire forum that shows the setup we've been using for the last 3 yrs or so. Only difference in my setup is we chose to use a DOM steel tube in place of the Aluminum one for superior strength {Mod edit:FALSE-only when same size and wall thickness tubing is used. Steel is a lot heavier. Pound for pound, aluminum thicker wall tube at the same weight as steel is stronger. Aluminum is more expensive. CM tubing is lighter than both steel and aluminum, thus can be used much thinner wall for weight savings over steel while retaining the same needed strength tube}. Use of dissimilar metals (steel threaded into Alum.) will cause galvanic fracturing and accelerated corrosion.{Mod edit: True only when uncoated metals are used-thus FALSE in this case. Steel rod ends are generally zinc coated and aluminum is anodized. Steel tubing is fine on a race car where the steel tube does no see a lot of water. I would not suggest steel in this application for a daily street car-WHY? Threads will rust over time and you will loose adjustment ability through corrosion seizing} where Same Speedway 4-bar ends are used. This particular setup has been thoroughly tested in the World Of Outlaws series and is made to collapse the tube during a horrendous crash which saves on destroying other components which was happening with the use of solid bars {Mod edit: False- Aluminum hex tub is commonly used}. I highly recommend that you grease the threads and run them completely in and out of the tubes to make sure they don't seize and remain easy to move. Especially helpful for those that are autocrossing and want to change their settings from street by throwing in some neg camber for racing. Also coat the inside of the 4-bar, the inserts and the bolt for complete squeek free fit. A smidge of blue Locktite on the nuts also helps{Mod edit: You do not need locktite. Jam nut use eliminates the need. Loctite harms threads }. I have this setup on both of my Xfires for the last 3 yrs. without a peep. Both are at factory height, but they both experienced the premature wearing to the inner rear treads, which is very common on the larger Xfire rear tires. Before installing these I would only get maybe 15K out of the rears. After installing these I got over 42K out of my last set, saving me a butt load of cash.
I've also sold this same setup to a buddy who is a MB mechanic with the local Firestone and he's installed a couple-o-dozen sets on different model MBs with perfect results. I included some of the pics from 202brabus first post and there's a YouTube vid @ the bottom of the thread showing the complete removal and install process. Also, all parts have links included and the prices have been updated as of 2/19/2015.
http://www.crossfireforum.org/forum/...tml#post712854
FYI - Here's the link to the YouTube vid incase it'e not viewable....
https://www.youtube.com/watch?v=8xS5UZZBWFM
{Mod Edit NOTE: than eliminate this post, I felt it was more important to keep some very common misconceptions and provide actual data.
Dean}