Autolite Plug Question!

91LX_5L

Founding Member
May 13, 2002
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36
British Columbia
I went to the autoparts store that carries Autolite (im in Canada) and I told them I wanted 3924s or 3925s. They said that those are not the right plug there smaller for probes etc.

They told me I needed Autolite 25s.

I have H/C/I (iron heads). I thought all you guys with iron heads ran 3924 or 3925? Or do I have my numbers wrong and he is right?

Also he said to gap at .054 I was thinking .050 is that good?

THANKS AND SORRY FOR THIS STUPID PLUG QUESTION AGAIN!
 
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yours iron? see the guy said 39xx are tottaly wrong and that " 'you' guys are lieing to me". and that I need 24/25s.

So 3924s/3925s will be fine? I've been told to run the warmer plug possible is that true so which should I run?

thanks again!
 
the major difference between the two is the reach the 24/25 has a 0.460 reach while the 3924/3925 has a 0.750 reach so its really going to depend on the head you have.
 
sorry for being ignorant but would .050 be optimal for me? I've never really gapped plugs before...stock is .054 some people say .045-.048 so yea what do you think?

thanks again man wish I could help u in return :)
 
cavscout371 said:
yeah thats damn close to what where paying here in uspstate, NY its like 2.60 american gal (which I think is basically 3 liters) for premium it sucks :notnice:

I was in Ogdensburg Ny today and the gas was 2.43 or 2.63 cant remember. A US gallon = 3.8L CAN. So basicly I did the conversion and by filling up in the states I was saving about .15$ per liter, from what we pay around here which is about .90-.96$/liter lately...:notnice: You guys are still paying the gas way cheaper than us.

And BTW-------------------> This is my 3000posts :banana:
 
Depth of the spark plug is the issue here, not warm/cold. It depends on the heads.

If you had the heads off, I could tell you instantly, but with the heads off the car, you need to consult the manufacturer of the heads, or find an article which uses them to tell you the proper depth plugs.
Scott
 
mo_dingo said:
Depth of the spark plug is the issue here, not warm/cold. It depends on the heads.

If you had the heads off, I could tell you instantly, but with the heads off the car, you need to consult the manufacturer of the heads, or find an article which uses them to tell you the proper depth plugs.
Scott
yes thats the reach (reach = depth) issue I that I resolved for him the heads have a stock 0.460 reach and not the longer 0.750 reach I got it from world themselves.