my mustang had 58,000 miles when i bought it,and i just changed spark plugs,and the gap on the old plugs was .43 and they all looked great,so i put the same type plugs back in which are autolite,764s and gapped then the same.i know the gap is supposed to be .54,but if i try to gap them to .54 it just looks too wide,any ideas,what do you guys set them at?

 

Just went through the same thing with my '96 earlier this year. Went to do plugs, pulled the old ones at 82k and they looked virtually brand new with a gap of about .043-.045. Just regapped for the spec's .054 and let it go... Seemed to pick up a small about of throttle response and mileage but I don't remember anything dramatic.

Edit... I hope you didn't try to gap them at .54 as thats over 1/2 of an inch!

 

i gapped mine at .053. thats what the gap was when i pulled them out as well

they should be between .053-.055 if i remember correctly

 

I think you're right with that range... If you're using a double platnum plug you'll see VERY little gap growth. Combine that with a fairly effective ignition system like our cars have (EDIS or COP) and I can see no reason to run a conservative gap.

 

i was wondering why you said not to gap my plugs at .054,but you did?

 

In your original posting your said you gapped them at .54" -- which is a bit over 1/2". Should be .054", 54/1000ths...

 

Get out of here with your math Mr. smarty pants!

Cliffy's just busting *****

 

In open air a GT COP would probably fire a 1/2" gap...

 

yea,i see my mistake,should be .054.my other question is,when i bought the new autolites,764s,the gap was at .045, the same as my old plugs,but if i try to gap the new plugs at .054 like it is supposed to be,it makes a slant in the gap? it is hard to gap them to .054.can you tell me what is wrong?

 

You are obsessing over this. The tip of a platinum plug is small enough that the side-electrode being slightly canted is irrelevant--gap the silly things at 0.054" and stick 'em in...