[Bill Edgeworth]

Just something everyone should know about timing lights;
The inductive pick up in most utilize ferrite. This is a magnetic ceramic material used to make the nest that the wire fits in in the pick up.
Ferrite is a very fragile material and if it cracks the performance of the pick up will be compromised.
better timing lights usually have the core encapsulated to help prevent this but I have a $400 Snap-On one that I once cracked the core trying to fit it on some real fat wires.

So what you think is noise could be a timing light problem.