in my 5.0 i useto run autolite, but im not too familiar with the mod motors, i just bought accel coil packs & 9mm ford racing wires. which spark plugs should i use? to get the best performance.

 

i would stick with auto lights. i knew a guy with a 10sec. 03 cobra that was still running autolites in his car. i take it u own a 96-98 4.6 due to using the wires.

 

Autolight xp's for me but then again i am boosted and have to go a range colder. Autolight is the best plug for anyford.

 

k now my next question, what gap? in my fox i gapped the plugs at 0.054, i remem seeing something on here for 0.043, then my friend had a 99 gt he gapped them at 0.034. so what should i gap the plugs at? and yes i have a 97 cobra.

 

I use the NGK plugs. Plain old copper core. No platinum as they can melt and are marginal at best for any kinds of improvement. They are used for longevity and that's it. Copper is the best conductor. I ran NGK's and have had zero troubles. TR6's gapped at .055" for me with 93 octane and the same accel coil packs. I have datalogged numerous times through out my tuning and seen no apparent side effects with that gap. It's one heat rannge colder than stock as I believe stock is a bit hot anyways. NGK TR55 is stock heat range. You should start out with .040" with your set-up and work up from there. Don't go much more than .055" since our cars run up to 6800rpms and you could have a break in spark. Not that you need to run up past 6k since there is no power past that point, but if it makes you feel good then it's your car..lol
I have a custom tune and use 93 octane. LT headers and freee flow exhaust. ram air intake as well.
.030" for boosted or N20
.035" for stock N/A
.040"-.055" for upgraded N/A ignitions

Stock heat range NGK TR-55
one step colder NGK TR-6