On the back it words it to as if i dont need to gap it and the way it comes from the factory is good. But it comes pre gapped to .45 and ford reccomends i gap it to .52 to .56 so what should i do? i already installed them with the factory gap but ill take em out if i have to. what will having the wrong gap do

I recommend .048-.050.

what does the difference in gapping do? anyone else have nething else?

if you stray away from 0.050 you be wasting gas. i believe you are still good from 0.045 to 0.055. anything past that and you need to pull those suckers out and re-gap 'em.

Originally posted by Alec
I recommend .048-.050.

Based on what?

Im no EE, but...

Fords ignition systems are good, and a big gap if you have the power will provide a big fat spark, more complete combustion, power etc.

I would gap the plugs to the factory specs on most plugs in a stock or close to stock engine. No reason not too, unless you are running some outrageous compression or maybe forced induction. Even then todays ignition systems should be able to handle the bigger gap.

Gap creates a certain amount or resistance combined with the fuel/air mix- more resistance the more power it takes to overcome it, the bigger the spark. The Air/fuel in the CC makes it a bit harder for the plugs to spark. Gaps too small and you get less bang, gaps too large and the ignition system may not have enough uumph to get a decent spark across the plug.
Too Large or Small and you will get misses and incomplete combustion.
If the plug mfr has a reason to run a specific gap thats different from the factory I would give them a call and ask them why? Make sure its tailored to your vehicle and not just a generic recommendation.

Anyway, I would stick with the stock specs, or if the plug manufacturer recommends something different try it - you can change it if it doesnt work well. But I would call them and ask first.

ok if i go out there rite now and regap em, what do i have to regap to on my 99 sohc, it reccomends .52 to .56 so should i put it at .50 or what

.048 gave me the best power and mileage. Also the less gap the longer the plugs have the potential to last.

If you want to stick with OE spec, go with .052, the lowest.

what kinda plugs u got alec?

I ran Motorcraft double plats, one heat range cooler than stock for the s/c and nitrous.

so if i gapped my plugs at .48 id be the best overall? i jus want gas milege, im anal about gas milege, i do everything i can to get more.

That's just my suggestion, do whatever you want with the info, and I bear no responsibility for outcome ;)

was .48 for jus superchargers or what, u dont understand im such a bad decision maker, tell me what i should do for my sohc lie to me somethin to make me sure cuz i hate this desicion making stuff

Originally posted by Alec
.048 gave me the best power and mileage. Also the less gap the longer the plugs have the potential to last.

If you want to stick with OE spec, go with .052, the lowest.

ok fine .48 it is, i hope ur right!

I gapped mine at .55 because the sticker on the radiator support said I should gap it between .54 and .56. Now the engine run a lot smoother and gave me better gas mileage. But I guess it's up to you on its gapping.

On a side note: Not to be an a-hole or anything but limit your signature to 6 lines so we won't eat up all the bandwidth.