IVR4 is what ? I'll guess aftermarket solid state electronic regulator. You're guessing that could produce static because mechanical points produce a "pop" noise. The same capasitor employed to reduce/remove your static would be anyone's guess.
The thing is... what you're reporting is one I haven't heard before. If the vehicle hasn't been moved since the change, move it enough rule out electric interference produced by overhead wiring, florescent lighting, etc...