Not sure where the C class info is from mate, it stands on its own to be honest with you.
Mo's right on the engines it will be 172, but they do have some mods for the facelift but not for the 171473 (SLK55)
I think you mean the CLK mate, the CLK uses parts from a C.Yes, I agree. I have an SLK and a C class parked side by side in my garage. They share few components. For example, the cowel height on the C class is over 6" higher than on the SLK. I think that the author of the article meant to say was that the C class and the CL class shared components -- and that would be true. However, the engine and transmission in my SLK is shared with the current model C class.
But I think the OP askes a question I have asked often -- why do we not have an R 171 SLK 63 AMG? Would I buy one? I'd certainly try.