Thank you guys for all your answer, im greatful for all ideas. Maybe i should try with one step hotter plugs and set the idle mixture for best idle and see how it looks after some driving.
If possible, attach some pictures showing a side shot of your plugs so we can see how many threads are getting colored from the heat etc. Ideally, they should have color down to 3 or 4 threads. I have to run a different heat range on several of my cylinders to get the same thread coloring.
I haven't messed with that type of car before, but 12 to 13 A/F ratio is too rich. Can you lean that out a bit? Maybe by dropping the float level a touch, or altering the jetting?
