interesting - I would have thought AMG would have used top quality materials for the valves/springs - stranger things have happened with these cars though.
But I do believe the SLK32 has forged pistons and CRods etc as opposed to the X320 series which I believe are of lesser grade....not sure on springs and valves.

It's strange the SLK32 redline rpm hasnt been re-rated when compared to the X320 series, but some reports (32Krazy et. al.) have indicated the SC runs out of efficiency above 6000rpm and going to 6500rpm as he did, held little if any gains.

Always the optimist, Id' like to continue to challenge some of this previous work.
Heading for 19+ psi boost (on the 61/155mm pulley config) and consistent 50C (122) Max AIT's and <13AFR in my SLK32 - but a lot of work (maybe a year) to get to that ellusive >320kW to match the car's namesake. Will all be worth it in the end.