I like the looks of that plug
I would lean down the thicker step on the primary metering rods by .002 to .004 and see if it drives good and makes the plugs run cleaner at part throttle cruise or not.
I'm assuming you don't have a lot of choices on where to buy or get Carter or Edllebrock metering rods in Sweden so I hope you can find some like I'm suggesting, don't change the bottom step if you can
If you get a set of rods like I'm talking about drive the car enough to warm it up without getting on it hard , drive it easy and then check the plugs, listen or feel for detonation or pinging, if you hear it or feel it let off the off of the throttle and put the old rods back in it as soon as you can