Also, the old springs may have been so weak causing the car to squat lower than factory. Also, remember there is different colors on the springs. Some are 2 blue 1 yellow example and springs are vin coded specifically to certain models. For example, a 280CE may have a different spring than a diesel because of the weight of the engine. Also as Frank mentioned there’s nubs on the springs. 4 dot could indicate 12mm for example and a 3 nub could indicate a 10mm.

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Only diesels in this driveway.
2005 E320 CDI 243k Black/Black
2008 Chevy 3500HD Duramax 340k
2004 Chevy 2500HD Duramax 220k