Should I disconnect ballast resistor when using MSD ignition?????????????????????

MSD makes one simple statement in their destructions:

Ballast Resistor: If your vehicle has a ballast resistor in-line with the coil wiring, it is recommended
to bypass it


There is NO reason to run a ballast with an MSD. The actual power to the box is battery (the "big red") and the small red is simply a switching trigger wire.

The way that the MSD provides spark is to apply a large (actually several) pulses to the coil. You do NOT want a ballast in the coil primary circuit.