[buzzinhalfdozen]

OK, well I've never used any MSD wire but let's assume they are NOT the cause of the interference. Do you have an alternator, electric fan, electric water pump, and are any of them on when you're trying to time the engine?Also does the timing lite have what looks like a flash every other revolution or is it pretty much on? Have you tried indexing the rotor, do you have a steady lite doing that? Maybe try merely trying to get a steady strobe by moving cables around and see if you can get that first. You say it's a crank trigger set up, are there any wires near your crank trigger wiring? Sorry for all the questions but it's harder to find the issue without actually seeing the set up first hand. One other thing you could try if you have one...put a spark checker on one of your plug wires and see if you're getting normal spark or extra spark events.