The red plug tip is in a YJ 4.2 with a carter BBD 2bbl carb. I almost have the feeling that the cylinder was not firing. But it's my sons and I only noticed it when it died about two weeks ago when the ecu went belly up. I just happened to pull that first plug to see if it was getting spark. The plugs that were in it were bosch, now I replaced them with autolites but the venturies are dripping again at idle. I'm going to drill them out tomorrow and get rid of that funky crimped taper they have. I also need to find a welders supply and pick up a set of those gauges for cleaning out the tips of the varnish that builds up in them. Carb cleaner, literally, is not cutting the varnish. I also want to run a compression check on that cylinder and make sure the valves are working correctly. Man, these straight sixes are just so much easier to work on than all the v6 and v8's I've had. I'd love to be able to afford a holley FI setup for it, among alot of other things. That price is for the big HP wires, I think they were actually cheaper than the stock OEM's. Might try the local dodge dealer down the street and see if they can order them, save a trip out of the way to the jeep dealer, I don't have one nearby, closest is 30 mi away.