Hi Bob,good eye!
What you are seeing is part of the reason I use the software I have for this dyno. It allows me to look at the data without all the data dampening some other software uses. It reveals some things other software won't
If you look at the graph closely you can see that the MSD and Blaster combination does the same thing,but earlier(6100 rpm).
For whatever reason the other setups did it at a higher rpm. When I first started seeing this happen I thought it was a valvetrain issue,but airflow data showed that not to be the case.
I can smooth out the data to keep things easier to read but I don't learn as much that way.
Keith