Get a MSD. They are great and makes your sparkplugs last longer. If you have plugs that foul out all the time, get a MSD. It also saves on fuel.

 

I use NGK "V" plugs and haven't had any problems. Did hear a few times about Motorcraft platinums failing in some other forums. For some reason most spark plug forums I have read do not particularly recommend Bosch platinum plugs for use with Mustangs. Lots of good press for the Denso plugs. I think they are something like $10 to $12 each! I used to run Splitfires in all my cars but I have heard from many mechanics over the recent years to stay away from them for a number of reasons. Not as popular by a long shot as they used to be. There is a new product out on the market that uses a different type of electrode set-up but it is so new I have even forgotten the name (what the hell good am I?). Here are a few sites to get background info on plugs: http://www.denso.co.jp/PLUG/iridium-e/ http://www.volvospeed.com/Reviews/iridium.htm http://www.silverbulletrx7.com/plugs/ Hey, I might have remembered one of the newer plugs. Check this out: http://www.briskusa.com/ They show a Mustang Cobra right on their web page. One of many testimonials: http://www.briskusa.com/testimonials_02curtis.htm Pretty wild numbers!

 

plug wires and igintion are more important then the plug mian thing is to get the right heat range......

 

i had the platinum 4 and they did not last long, so i use autolite the $1.98 ones

 

Side-gap them.

 

The problem with the +4's is that you have 4 electrodes to arc over. A normal plug has one (obviously). A stock ignition, or aftermarket, as far as that goes, wont have as much heat to the spark if it has to bridge 4 electrodes instead of just one. Another thing, as far as platinums go, Platinums were designed to that the recieving side of the spark has a platinum coating to resist wearing down as fast. Double platinums coat both electrodes. These are used in some newer (mid 90's and up) cars that actually fire both ways-- that is, they fire from the upper electrode to center electrode, and vise versa. GM Delco's are known as 100,000 mile plugs, but you'll pay about $10 a piece at a parts store ($80 for a V8). Otherwise, you can go buy some Autolite 25's, give or take, depending on what you are running, for $1.50 a piece ($12 for V8) that will last 20-30,000, depending on your ignition and wires. At that lifespan, over the course of 100,000 miles, you'll save $20-50 over double platinums. Platinums wont give you any more performance either. A lot of these "special" plugs are little more than an electolicized coating over a normal copper plug, that gives you little change in life/spark, and charge you 4 times the price. Its your money, but I'd stay with regular plugs.