Petronics sells 2 60k coils, both at the same price @ 70 bucks. BUT! Each has a different Ohm rate: .45/.6O Ohms (with no explanation as to why or what to base your choice on. The intended recipient is an 87' F-150 5L w/brass cap & rotor, msd superconductor/low resistance wires & running side gaped copper motorcraft plugs at 17BTDC w/ 87 octane. Fixin ta MAFotize it in the next couple of weeks and eventually add an ignition controller. Right now it's limpin along fairly well w/ the stock coil. My original intent of the H.P. coil was to gap up from .044 to .056 but the results of a my side gap expeariment done to relieve a sunday's boardome has me woundering. It increased overall performance a bit AND 2 MPG w/ a .043 gap at whatever stock coils put out (20k ??) I'm wondering if a 45k coil would be enough or am I better off sticking w/ the 60k coil choice. Initial cost is not an issue, but both coil outputs offer .45/.60 Ohm models. Sidebar:Why doesn't any plug maker make a 2x Plat side gap plug that would be able to provide stock ignition systems w/ better performance & gas milage w/o the cost of plugs life? The concept is public domain. It's not like somebody is sitting on a patent.

 

ymeski56, Sounds like your doing alot of good things with your truck to boost performance, ignition is always a good upgrade.

I personally use and recommend the Pertonix E-core coils IMO they are the best coils on the market for less then $100 (which is what your talking about right) there are 3 part #'s;
60130 is 3 ohm and is for 4cyl engines.
60115 is 1.5 ohm and could work on your truck.
60104 is .45 ohm and is the best choice.

Why, having a low resistance coil gives you the most options and best starting power. The coil resistance is there to add too or use soley to lower the amperage through the pickup or module. There are problems though with having this resistance, during cranking the voltage available drops, this with too much resistance can drastacaly lower the amount of power the coil is able to provide during startup making the truck harder to start. Ford has always had the solution though it is the "I" (for ignition) post of your starter silenoid, this post is only hot during cranking. If you use a seperate resistor (ballast resistor) (I like the Mallory #700) and a low resistance coil you can wire it so the resistance of the seperate resistor can do the job of lowering the amps while running so your pickup will live, but bypass it during cranking to provide the best spark while starting the engine. If a higher resistance is used in the coil and no ballast then the resistance is fixed and spark will be weaker during cranking.

Edit, Just relized you're fuel injected, your system has a built in resistance, I beleive your factory coil resistace is quite low use the .45 ohm #60104 and no resistor unless willing to really get into your trucks wiring.

Other things of note;

IMO the Taylor Thundervolt 8.2 wires are a better choice over the MSD if you haven't bought them yet, But MSD makes the best caps.

You are better of with as much coil voltage as you can get.

I don't know what else you intend but IMO MSD spark boxes are a waste of money and only add to things that can go wrong.

They do make side gap platinums though I haven't yet checked them out and I don't beleive any would fit your truck. All rotary engines (RX-7) use side gap plugs because the electrode would hit the rotor, but the threads are differant then your motor. Back in the day I ran rotary plugs in my race Datsun, that was my first experament with side gap plugs and proved to be a great success. I haven't looked into them in a while though because I am happy with my home made side gap autolites and there alot less expensive.