Denso spark plugs will not cause RFI. Denso has been OE on Corvette since the late 1990s.
Super Conductor plugs wires do not normally cause RFI, either. In fact, the original application for the Super Conductor design was NASCAR Sprint Cup cars with two-way radios. The Cup guys wanted a plug wire that would provide low resistance for maximum ignition energy but high supression to reduce the effect RFI had in their radio signals between the driver and the spotter and the driver and the Crew Chief.
I have Super Conductors installed on every car I own that uses plug wires. I have Denso Iridium Power plugs in every car I own, both high-performance and daily drivers. I do not have trouble with RFI.
The Densos to put in an LT4 are IT-20s. The Super Conductor set to use is 32179
Lastly, in re: "93Rubie's" post...how do you tell that most Fords don't "like" Autolite or Champion spark plugs. While I'm not a defender of those brands, I must admit, to make such a wide ranging statement covering seemingly all Ford engines and two major brands of spark plugs, you must have extensive experience working with Fords. Are you a veteran professional service technician working for a Ford specialty shop or a Ford dealer?
Hmm, learn something everyday...regarding the Super Conductor wires and Denso plugs.
Yes, that is a broad statement, about Fords with Champion and Autolite Plugs. I am a tech at a Ford dealership, not a veteran but I work with two of them. One is a Senior Master, the other a Chassis and Engine Master. I was diagnosing Lean and Misfire Codes in a 3.0L Escape, had misfires on 1,2, and 3. The rear bank on a Escape 3.0 V6. I found the "cause" of the lean code, when I opened the hood,I could hear the vaccum leak, some jack off, decided that heater hose was an acceptable replacement for a PCV elbow. I happend to have one laying around and put it on, which shut it up. Then continued with the dianoisis.
I pulled a plug on the front bank just to take a look. Thing had 140000 miles on it, service history unknown. Had Autolites in it, the Senior Master took one look and said, "Well there is your problem." He told me don't ever use autolites or champions in Ford engines. They don't seem to run like they should. As a young guy,22, I don't take what everybody says as gospel, but it is almost gospel, when it comes from him.
To end my story, I pulled the upper intake(to do rear plugs) and put some Motorcraft plugs in it. Ran much better but when cold it ran like poop and my fuel trims where still shot to heck once in closed loop. I determined that the lower intake manifold gaskets where bad. Now I showed this to the Master Tech and asked for his 2 cents worth. He said, he had never seen those go bad, but it appears they are. So I replaced them and voila fuel trims in line and drivability was perfect. We figure whomever put in the Autolites didnt properly torque the manifold down, as the spec. is only 89 inch pounds. They were much tighter than that when I took them off. This caused the manifold to become tweaked and caused the seals to leak.
