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Just got off the phone...there is NO difference....they will BOTH sit at the same spot. Garrett es muy caliente..I know that doesnt make much sense...but I only know soooo much SPanish The plugs go in tonight.....And esta noche, bailamos!
After your done, while your still under there, spray all your plugs and wires and everything (except your fan belts) with Silicone spray. It will water proof all your electrics, keep dirt and oil from sticking to your motor, prevent arcing from your plugs or wires and generally protects all metal, plastic, and rubber parts. I use the stuff liberally on my truck every time I open the hood. My engine compartment NEVER gets dirty, simply because dirt wont stick to anything, and I can pour 50 buckets of water on top of my motor and it'll still start.
The thrwead should be the same regardless of heat range!! The heat range is determined by how much metal is between the threads and the hex for the socket. It acts as a heat sink.
I would run 1 or 2 heat ranges colder than stock to help keep detonation down. Detonation under boost will ruin a headgasket and maybe more if you are unlucky.
Make sure that you have plenty of fuel too!!
Jimmy
GARRETT, I is important to note that when you are running a power adder, be it nitrous or an SC, you need to run a colder plug.
Colder plugs WILL NOT extend as far inside your cylinder as normal temp plugs, therefore it is perfectly normal for your colder plugs to have less threads. It is the intention of the plug to seat more shallow in your cylinder.
If your unsure, Autolite 764's are proven tried and true. Just about every single high performance mustang out there uses them. They are 2 full steps colder than your stock plug and are not platinum. They too have less threads on them than the stock plug.
Install the plugs and start the truck. The colder plugs will also reduce gas mileage, price paid for power.
Tom
To re-quote myself regarding the colder plugs in a power-adding scenerio.
The ceramic core combined with the positioning of the electrode is what disipates the heat. At least from everything I've read coupled with the 400 threads regarding this very subject. Colder plugs WILL definately have a different thread layout than stock plugs, everytime.
Garrett, This subject has been argued so many times it makes my head spin. It's like that 8 page OIL thread we had going that one time where everyone was arguing why one type of oil is better than another. Just use the plug that is recommended for your SC (should be 2 steps colder) and gap them at the recommended gap. They do NOT come gapped out of the box.
Serious, if you really aren't sure, go to the auto parts store and buy 6 Autolite 764's for $7.74 and gap them at .035.
Here's some info from Autolite's Website.
Spark Plug: Heat Range Facts
Typically, engines which are stock or are only slightly modified, can use the original equipment (OE) recommended spark plug.
Racing Modified Engines- Generally, any engine modification that alters the overall compression ratio of the engine will involve spark plug selection issues. One thing to consider is heat range. The heat range of the spark plug determines how much heat the spark plug is capable of removing from the combustion chamber.
The heat range of the spark plug does not increase or decrease horsepower. It changes the temperature of the tip of the spark plug. If the heat range is too cold, the deposits will not burn off the tip and the spark plug will foul. If the spark plug heat range is too hot, pre-ignition can occur.
A switch in heat range of the spark plug will change the temperature of the spark plug tip by 70-120 degrees.
If you are unsure of the correct heat range to use, always start with a colder spark plug. If the plug is too cold, the plug will eventually foul and a misfire will occur. This will not hurt the engine. Unfortunately, though, if a spark plug that is too hot is inadvertently chosen, preignition and detonation can severely damage your engine. Don't go to a hotter heat range unless you've consulted your engine experts.
As there are many different ways to modify your engine for racing applications, we can't tell you here which specific spark plug to use. If you have made modifications to your engine, you should refer to your component manufacturer's specifications and/or contact the experts at Honeywell at www.autolite.com.
Thinking about the plug thread issue we were talking about, I ran down at lunch and took a close look from under my wheel well, which is easy now that my truck is jacked, and what I thought were exposed threads before is actually just an extended seating jacket and not threads. When I installed them from the top of my truck (prior to my lift) it appeared as if they were threads, but their not.