Ron,

I checked the MSD instructions and the ballast can be kept in place (or removed) because it is bypassed by the MSD ignition module. This implies that it shouldn't be having any effect in circuit.

Instructions can be found on this link:

http://www.msdignition.com/pdf/6%20series/6series.pdf

Aside from the ground wires, what about the supply side and trigger sense wires?

Does the pop and miss take place only when accelerating, cruising, at idle, all of the above?

Mark