have you confirmed the NW inconel? headers will fit a LHD? SLK32...?
Will the SLK32 be your test car or are you looking at an SRT6...there are some differences - eg: final drive ratio (different sized wheels*), possible different cams...there has been some discussion about this in the past...etc..


Maybe before and after torque chart is the best measure....


*Final drive tratio in 1st gear is 11.0 v 11.5 for the SRT6