All I know is that I run a MSD 7AL2 box. I wanted to see how much noise there was on the grounds from the box so I dug out my scope and Rogowski coil. Bet most people don't know what a Rogowski coil is - it is a flexible core current transducer. Mine has a bandwidth of 5 to 8 mhz so it is designed to measure high frequency current.

There was so much noise it was impossible to measure. I got no idea how any of the electronics works with all that noise....

That convinced me to follow MSD's installation instructions to a t!