460 Spark Plugs
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Senior User
Joined: Feb 2015
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From: Northcentral Missouri
460 Spark Plugs
Ok, when I installed this motor last year, I just got new plugs like the ones that were in there - Autolite 45..... Saturday, my wife went to the parts store, and they gave her Autolite 25's.
Which one is it SUPPOSED to take? This is a 1979 (ish) 460 in a 1986 F-350.
I'm thinking the 25's are correct......what is the difference between the two?
NATURALLY, when I go to change them, the parts store is CLOSED
Which one is it SUPPOSED to take? This is a 1979 (ish) 460 in a 1986 F-350.
I'm thinking the 25's are correct......what is the difference between the two?
NATURALLY, when I go to change them, the parts store is CLOSED
pedant
Joined: Jan 2008
Posts: 23,576
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From: EXTREME southwest CT
25's are the right number for DSII ignition and .044" gap
I have had quality control problems with Autolite's and recently switched over to NGK UR4's.
These are their regular copper V-power plugs
I have had quality control problems with Autolite's and recently switched over to NGK UR4's.
These are their regular copper V-power plugs
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Senior User
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From: Northcentral Missouri
Ok.....I guess I DIDN'T replace them last year! I went to install the 25's and they WILL NOT WORK! The 45's are a large plug (13/16 socket) and the 25's are a small plug (5/8"). They are also smaller diameter across the threads. I guess now I know for sure what to use, even though parts houses tell me different!
pedant
Joined: Jan 2008
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From: EXTREME southwest CT
If that's the case and the engine has been swapped the only way to tell is to pull the pan and look at the numbers stamped in the crankshaft.
U vs Y.
This will tell you what the stroke is, EVERYTHING else is the same between 429 & 460's.
What are the head casting numbers?
D0OR, D0VE, or maybe the D1VE?
U vs Y.
This will tell you what the stroke is, EVERYTHING else is the same between 429 & 460's.
What are the head casting numbers?
D0OR, D0VE, or maybe the D1VE?
pedant
Joined: Jan 2008
Posts: 23,576
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From: EXTREME southwest CT
Just now for $#!*$ and giggles I went to Autolite's site and looked up a '73 Tbird with a 429.
...calls for the same #25 peanut plug.
It's REALLY strange what you've got going on
...calls for the same #25 peanut plug.
It's REALLY strange what you've got going on
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From: Northcentral Missouri
BUT.....in 1971, that same T-bird 429 takes 45's......
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Senior User
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From: Northcentral Missouri
Well, it's in an 86, so the motor has to be pulled loose to drop the pan....so....that ain't happening! I will see if I can figure out what heads I have. They guy who had the engine before MIGHT know what he got it out of....
pedant
Joined: Jan 2008
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From: EXTREME southwest CT
Ahhh, The super craptastic low compression open chamber D1VE heads....
Eight years before the 1979 engine you suggested it was.
Eight years before the 1979 engine you suggested it was.
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Senior User
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From: Northcentral Missouri
All I know is - it canme out of a 1979, I have NO idea where it lived before that. I was TOLD it was a 460 - and it still MIGHT be.....
pedant
Joined: Jan 2008
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From: EXTREME southwest CT
It could be 429 or 460.
The only difference is the crank throw.
Look for a number cast between the 2&3 head bolts on the outside.
429 ' s were never installed in trucks and not made in 1979.
The only difference is the crank throw.
Look for a number cast between the 2&3 head bolts on the outside.
429 ' s were never installed in trucks and not made in 1979.
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Senior User
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From: Northcentral Missouri
I know.....that's why I originally thought it was a 460.....
Ford Parts Specialist
Joined: Nov 2006
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From: Simi Valley, CA
As original 1968/79:
1968/72 429 = BF42 or BRF-42 / 1973 429 = ASF-42
1968/72 460 = BF-42 or BRF-42 / 1973/76 460 = ARF-42 / 1977/79 460 = ASF-42
---------------------------------------------------------------------------------------------
429: 1968/71 Thunderbird / 1968/73 Ford/Merc Passenger Cars.
460: 1968/78 Lincoln/Continental Marks / 1972/76 Thunderbird / 1973/76 F100 / 1973/78 Ford/Merc Passenger Cars / 1973/79 F250/350 / 1975/79 F150 / 1975/97 E250/350 / 1983/97 F250/350.
1968/72 429 = BF42 or BRF-42 / 1973 429 = ASF-42
1968/72 460 = BF-42 or BRF-42 / 1973/76 460 = ARF-42 / 1977/79 460 = ASF-42
---------------------------------------------------------------------------------------------
429: 1968/71 Thunderbird / 1968/73 Ford/Merc Passenger Cars.
460: 1968/78 Lincoln/Continental Marks / 1972/76 Thunderbird / 1973/76 F100 / 1973/78 Ford/Merc Passenger Cars / 1973/79 F250/350 / 1975/79 F150 / 1975/97 E250/350 / 1983/97 F250/350.
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From: CA
Just took this of my 86 F350 1 TON 460
.43-.46 for the ASF 42 plugsIm assuming the 25's = 42's? ArdWrknTrk stated .44 for the 25's is this a standard (proven) number that works well for these? or just a good number in that range that is acceptable?
Thanks