7 hours ago
Nearly a year later and I've sussed it out so this post is for the record.
For Lucas distributors using holes in the base plate to control the maximum mechanical auto advance (the DK series), there is a linear relationship between the distance between the OD of both holes and crank advance.
So, if you haven't gone to Bosch 009 this chart may be useful.
Just measure the maximum across both holes, measure the diameter of the current holes and do some O level maths to see what size to drill the holes.
For Lucas distributors using holes in the base plate to control the maximum mechanical auto advance (the DK series), there is a linear relationship between the distance between the OD of both holes and crank advance.
So, if you haven't gone to Bosch 009 this chart may be useful.
Just measure the maximum across both holes, measure the diameter of the current holes and do some O level maths to see what size to drill the holes.