At the moment I am in the process of replacing the spark plugs on the 950SE. I wanted to try irridium so I ordered the CR8EIX instead of the CR8EK. Now I notice that the top contact for the ignition coil is different with the CR8EIX compared to the CR8EK. In the picture below you can see the difference. At the top the CR8EK has a thin threaded contact for the ignition coil. At the top the CR8EIX has a thicker and longer unthreaded contact for the ignition coil. With the CR8EIX, the spark plug contact doesn't fully insert in the ignition coil contact, so the ignition coil doesn't fully insert in the spark plug tube: When looking inside (from above) the thick unthreaded contact, it looks like there is the same thin threaded contact as the CR8EK has, and it seems like the thick part just needs to be removed prior to installation. The thick part has an inside thread. I tried to remove the thick part with already a fair amount of force, but unsuccessful. Can someone confirm this has to be removed or not? And if so: just with brutal force? Or am I missing something else?