Well I finally got around to swapping the blowers and putting new plugs (platinum Motorcrafts) and wires (factory replacement Motorcrafts) on the 'Bird (what a nightmare). Now that I've expected it to run better, I'm hearing a popping in the exhaust. Sort of sounds like a burnt valve, but it's not. The car runs 100%, no problems whatsoever. I'm not sure what the popping is. It's very quiet, you have to listen closely to hear it. It's also inconsistent, you can't count on it to pop every so often...just whenever it wants to. I'm sure the popping was there before the work I did, just didn't pay any attention to it. Any ideas? The car is all stock, including exhaust.