Looking at the factory manual, it looks like the AL arms were an option for the w123 and w126. They have an anti-squat function too. I was thinking about this a few month back while I was under a 450slc, it would be a nice upgrade.

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1998 Mercedes E300TD

1983 Mercedes 240D Turbo, 131bar injectors, Cosworth intercooler and 63' Ford Falcon radiator, Ardic Parking heater, Headlight wipers, Best 38.6mpg.

1973 Saab 96 Rally Car, 1.8l V4 with all the race bits