Seeing that the weight is not the issue, I'd say the SLK shocks are gonna work the same as the Newer style. Considering that the price at RockAuto for the newer ones is almost twice the price of the SLKs, I'd stick with the KG4731 & KG4732. Plus, RockAuto wants to charge over $40 EA to ship from United Kingdom (Great Britain)! The ones from AJUSA.com, where I bought mine, include free shipping! Like I said, mine have been on for around 4 yrs now and I'm very happy with the ride. Also remember that these are on my Limited. These might work differently on the SRT with the stiffer spring rates.

Another thing that has got me perplexed is that RockAuto is showing a different p/n for the newer KYB Europe shock on the SLK320. And at a much higher price I might add....553245 rear @ $126.79 EA and 553237 front @ $152.79 EA. --- BUZINGA !!!