You'll note here a "7" can indeed be correct for your car.
http://mb.braingears.com/124_DISC1/P...03/15-1031.pdf
This shows H7 was standard upto 2/87 and on 103.980.
As my engine is 103.983 and a euro model, I should be using H8 for normal compression and H9 for low compression if I understand it right or do I ?
Again it seems as per the manual if I use H9 I should not drive over 160Km/hr.
To be on the safe side should I use H8. what will I be sacrificing if I use H8 or after reading this link what do you think Duke2.6, should I still use H9.
I rarely would drive above 160Km/hr and only if challenged and that too in short bursts.