My car is still Positive earth , timing light worked fine , low price e-bay job
Theoretically you should maybe swap the coil connections but it’s far from being essential. All that happens is that spark erosion at the plugs etc will take place on the opposite electrode. Having only done 25k miles in the 25 years of ownership of my car I don’t consider it a big deal and if I remember correctly I didn’t bother swapping my coil connections.
Thank you, Peter.
I think I’ll leave the MKV with positive earth. It was an interesting discussion for which I’m grateful, as always.