258 Engine ID and head bolt size - Off-Road Forums & Discussion Groups
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post #1 of (permalink) Old 02-17-2002, 02:30 PM Thread Starter
 
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258 Engine ID and head bolt size


my engine ID is 3 05 C 26. According to my tech manual that's the built date code and means :
26th of may 1979 258. (my CJ 7 is an 1983 though)
I read somewhere that 79 engine should have 1/2 head bolt whereas mine has 7/16 head bolt ?

what is correct ?

Thanks for your help

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post #2 of (permalink) Old 02-17-2002, 02:59 PM
 
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Re: 258 Engine ID and head bolt size

Post your block /head /or crank casting numbers and I can tell ya.The block # is on the passenger side below the front freezout plug.the head # is dead center between the rocker arms
Information I have hers says
75-79 1/2 " head bolts
80 unspecifiedmine is 1/2 " temp sending hole is top rear of head
81-85 7/16"
86 1/2 "
87-89 1/2"

Ray
Learn to let go of what does not serve you ,but forces you to serve it
why does everyone ask if I am gonna paint it ?
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post #3 of (permalink) Old 02-17-2002, 03:18 PM
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Re: 258 Engine ID and head bolt size

I'm pretty sure that the first number of the build code is the year. Hence, since your's is a "3" it means 1983. The rest of your date sounds correct. I have a 1984 and my build code also starts with a "3", but the month is August, which makes sense if my truck was purchased in late 1983 as an 84 model. The 7/16" head bolts also seem to confirm that your mill is not a '79.

TEXAS1AL

84 CJ-7; 258 I6; Restored-to-Stock Condition, TR Ignition Upgrade
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post #4 of (permalink) Old 02-17-2002, 03:34 PM Thread Starter
 
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Re: 258 Engine ID and head bolt size

That would sound logical. Then my engine would be the original engine thus I would know it's mileage ! (115 k)
I have a 1980 Jeep "Technical Service Manual" and in the identification section they say :
1st character (year) : 3-1979 4-1980
But then I do not have the 1983 version so I don't know what they did with years numbers afterward.....



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post #5 of (permalink) Old 02-17-2002, 03:35 PM
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Re: 258 Engine ID and head bolt size

I found out the definition of the code from "The Jeep Bible" and it sounds right.

Correction on the 115K mileage, you know it has AT LEAST 115K miles. Mileage is not an exact science in CJ's.

TEXAS1AL

84 CJ-7; 258 I6; Restored-to-Stock Condition, TR Ignition Upgrade
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