The issue I had that max mentioned was that NONE of the Magnecor wires seated properly when I initially installed them.
When Max and I were swapping my valve covers for the crinkle black ones, I found it very easy to access the plug ends on the wires.
I was then able to get a 'snap' from all 12 .....
Seems the long boots on the Magnecor's are a bit too squiggly to allow a good seat without grabbing them at the bottom and seating them.