Top end miss

We run a MSD 44 Amp mag with a crank trigger and 8147 rev limter box. Around 8000 RPMs before the finish line the car falls over and miss fires. Yesterday it chucked the belt off it was so unhappy.

I downloaded the computer and see around 8000 rpm the engine line had noise in it. Sounds like ignition problem. I contacted MSD and they want me to go through the plug wires, grounds, etc.. They think the noise is only at high rpm becasue of the pressure on the cylinders. I think the noise would be there all the time. I changed he Rev chip to 9400, no difference. Could the Tach interface module cause something like this?

Anyone ever had a problem like this?