98 vs 99 head gaskets
#1
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98 vs 99 head gaskets
whats the difference between 98 and 99 head gaskets? i thought the heads were 98 but they are 99s. will 98 stock graphite head gaskets work with 99 heads basically?
Last edited by DriveATransAm; 06-22-2005 at 05:32 PM.
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I've talked with a few shops about this and the general consensus is that grpahite gaskets were OEM used from 98-01 on the Fbody LS1's. In 02 and some even say late 01 models got the new MLS gaskets.
#6
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Check on the gasket if they have a lower notch.
https://ls1tech.com/forums/attachmen...chmentid=35007
That is a 99 head (853 casting). MLS Gaskets for that head need a notch.
https://ls1tech.com/forums/attachmen...chmentid=35007
That is a 99 head (853 casting). MLS Gaskets for that head need a notch.
Last edited by PREDATOR-Z; 06-23-2005 at 10:48 AM. Reason: 853 casting and gaskets
#7
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Originally Posted by PREDATOR-Z
Check on the gasket if they have a lower notch.
https://ls1tech.com/forums/attachmen...chmentid=35007
That is a 98 head. Gaskets for that head need a notch.
99 do not have that and gasket shouldn't either.
https://ls1tech.com/forums/attachmen...chmentid=35007
That is a 98 head. Gaskets for that head need a notch.
99 do not have that and gasket shouldn't either.
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#8
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Originally Posted by 2xLS1
Actually, I took that pic and it is of a head off of my 99, casting #853. Any 853 casting will have the notch and they were used through 00 MY. The GM graphite gasket will not have a notch there. The problem is if you use the 02+ GM MLS gasket with heads with the notch, it will leak coolant there. The graphite gasket seals around that notch and the GM MLS does not.
Doesn't the 97-98 perimiter bolt head have that too?
#11
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Originally Posted by Zick
My 98' has those notches on it.
So 97/98/99/00 have those notches, Graphite will seal them fine but MLS gaskets have to be specific to the year (unless the notches have been welded)
That sums it up.
Last edited by PREDATOR-Z; 06-23-2005 at 12:38 PM.
#14
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Originally Posted by ssheets
Is it true that you can use the graphite on either, but you can only use MLS on the non notched heads?
Also graphite are .055" and the MLS are .060"
Also graphite are .055" and the MLS are .060"
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Originally Posted by PREDATOR-Z
.053 compressed for the graphite (measured)
I'll be using the Graphites on 5.3 heads, with a compressed hieght of 0.053" a chamber volume of 59.25 will give me 11:1CR not sure if I can quite get there, but I should be close.
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#19
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GM MLS are thicker than graphite. .060 compressed. Not good for quench purposes.
Cometics are the good ones but good luck finding any in stock (3>4 week backup order)
Cometics are the good ones but good luck finding any in stock (3>4 week backup order)