Spark Plugs in ’68 Mustang
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=828
Printed Date: May-16-2024 at 11:57am
Topic: Spark Plugs in ’68 Mustang
Posted By: Jim_In_Houston
Subject: Spark Plugs in ’68 Mustang
Date Posted: September-16-2004 at 12:41am
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The spark plugs in my 1968 Mustang, Ford 289, are Motorcraft # ASF 32CM. They are stainless steel, 5/8" hex with 10mm threads (I think). I cannot find a source for Motorcraft marine spark plugs. The local auto parts house told me the "M" in the part number stands for marine and they don't carry the plug. What should I cross this plug with? Should I stay with stainless steel? Anyone know of a source?
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Replies:
Posted By: Tim D
Date Posted: September-16-2004 at 4:54pm
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I use autolite 26 in my 1966 mustang. They will rust around the ceramic part. But I change them every year (cheap). About 9 years ago I left the plugs in for about 4 years and the number 5 cylinder shot the ceramic part out of the metal part when I hit full throttle. The plug and plug wire hit the motor box, man what a noise, we thought someone shot a gun at us. Luckily the wire didn't get in the pulleys and belts. Last year I indexed all my plugs toward the intake valves, but I noticed they don't stay as tight because of the spacer washers. I took the points out about 5 years ago (the best $90 ever spent) and I use an Accel coil which is designed for heat and vibration, it has a gel instead of oil. ------------- Tim D |
Posted By: Jim_In_Houston
Date Posted: September-16-2004 at 5:57pm
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Thanks for the reply Tim D. Now I am convinced I should stay with marine duty stainless steel plugs.
So, how did you pull your points out? Are you saying you installed a solid state ignition? If so, what all will I need to do that myself? -Jim |
Posted By: Tim D
Date Posted: September-20-2004 at 4:40pm
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Those stainless steel plugs are about $4.85 a each. A regular plug is 84 cents each. You take the points and condensor out and replace it with electronic unit. Take screws out and screw in new part, very easy,(use a screwdriver with magnectic tip)and use the same rotor button and cap. My mustang has a flat top Mallory distrubutor.(had single points). It starts easier and made a big difference on throttle response, and I gap my plugs wider now. It was worth the $90, no more sanding points or replacing points, and moisture doesn't affect it. ------------- Tim D |
Posted By: Jim_In_Houston
Date Posted: September-21-2004 at 1:58am
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You sold me on the electronic ignition.... I don't mind the $5 spark plugs... I just can't find them.
-jim |
Posted By: 882001
Date Posted: September-21-2004 at 6:16pm
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jim i use autolite 24s the 88 cent ones. and use it in salt water, the same water you use yours im sure. i bought my conversion kit at www.vintageperformance.com it was 100.00 for the conversion kit and a high perf coil. you can order one for that mustang while your at it. ------------- kemah texas http://www.correctcraftfan.com/diaries/details.asp?ID=163&yrstart=1986&yrend=1990 - 1988 skinautique "2001" |
Posted By: David F
Date Posted: September-21-2004 at 6:42pm
| Go ahead and use automotive spark plugs. I have been doing so for the past 25 years with never a problem. Just make sure you use a conservative amount of anti-sieze on the threads. I also use dielectric grease on the spark plug wire boots to prevent them from sticking to the plug...makes for easier removal. |
Posted By: IrishFooter
Date Posted: October-09-2004 at 6:16pm
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I tend to agree with the majority on this one. Go ahead and use the automotive plugs, just be certain to change them in a timely fashion. AS Tim said bad things happen when you dont stay on top of the little things. ------------- 1979 Ski Nautique |
Posted By: Jim_In_Houston
Date Posted: October-11-2004 at 11:06pm
Well, I have discovered that my plugs are not the standard size for a 289 Ford. The threaded part is smaller in diameter and longer than plugs that came in that engine. Research shows the plugs I have, ASF-32CM Motorcraft, fit a GT-40 head. The only casting number I can see on the heads are "Ford" and "2T". Anyone have any idea of what heads I may have? The plugs all slant point slightly toward the front of the engine. The engine is supposed to be a 1968 289 but now I am even wondering about that.
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Posted By: reidp
Date Posted: October-12-2004 at 9:11pm
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Jim,
The casting ID number you need is unfortunately on the underside of the head. My guess is that you just have a later model, 1975+ head where Ford went to the smaller plug design. If you're so inclined or interested, which I'd be, pull one head, flip it over you'll find what you're searching for and then look at the link attached to see what you've got. http://www.mustangii.net/head.asp ------------- ReidP /diaries/details.asp?ID=231&yrstart=1971&yrend=1975 - 1973 Mustang |
Posted By: Jim_In_Houston
Date Posted: October-12-2004 at 10:20pm
| Oh boy.... now I have to pull a head... well what better way to spend a weekend... seems like I could tell by the rocker posts or spring lands... thanks for the info, you are probably right. Thanks for the link. |
Posted By: 79nautique
Date Posted: October-13-2004 at 12:04pm
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On the front of the head there will be three cast ribs or bumbs kind of like a bar code if they are gt-40 heads it will be between the freeze plug and a mounting boss for accessories but closer to the boss. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |