View Poll Results: Who has had heads leaking after installing .040 gaskets?
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Heads leaking after installing .040 gaskets poll.
Originally Posted by vettenuts
The Dart chambers are wider, I used GM 6.0 MLS gaskets on mine.
1. Fel Pro 1161L and 1161R
2. GM 6.0L MLS
3. Cometic
Bill,
You need to call Cometic and discuss the requirements to find out which gasket best fits your needs.
After calling Dart, and not getting much help, I called Cometic, and they specified one they make that is for a 4" bore. Part # H1295040S but keep in mind that is for a .040 gasket thickness. I layed a set of Cometics for a 3.901 bore on my Dart heads and they do overlap the chambers. I don't know if it matters any, but my heads have also been milled to 59cc's.
The only thing I could get out of Dart is that gaskets for a stock bore will not work correctly on Dart heads. I even layed down a set of GM MLS gaskets on my Dart heads, and even they overlap the chambers.
The only thing I could get out of Dart is that gaskets for a stock bore will not work correctly on Dart heads. I even layed down a set of GM MLS gaskets on my Dart heads, and even they overlap the chambers.
Thread Starter
Joined: Apr 2003
Posts: 2,597
Likes: 4
From: Lawrenceville, GA
Originally Posted by Captain InsaneO
After calling Dart, and not getting much help, I called Cometic, and they specified one they make that is for a 4" bore. Part # H1295040S but keep in mind that is for a .040 gasket thickness. I layed a set of Cometics for a 3.901 bore on my Dart heads and they do overlap the chambers. I don't know if it matters any, but my heads have also been milled to 59cc's.
The only thing I could get out of Dart is that gaskets for a stock bore will not work correctly on Dart heads. I even layed down a set of GM MLS gaskets on my Dart heads, and even they overlap the chambers.
The only thing I could get out of Dart is that gaskets for a stock bore will not work correctly on Dart heads. I even layed down a set of GM MLS gaskets on my Dart heads, and even they overlap the chambers.
Bill
Originally Posted by Bill Bowling
Would I have to get that gasket from Cometic direct? I do not even see that part number on their web site or anyone's web site. Sounds like a special order. Did they tell you?
Bill
Bill
Originally Posted by 99NMB
I would recommend just using OEM replacements for your 5.7 Ls1. They will be the right bore size... Just my 2cents 
Thread Starter
Joined: Apr 2003
Posts: 2,597
Likes: 4
From: Lawrenceville, GA
Originally Posted by Captain InsaneO
It's not a special order, he said they have them in stock they just don't have it on their website. I talked to Kevin at Cometic. They are $82.85 each I believe.
Bill
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Thread Starter
Joined: Apr 2003
Posts: 2,597
Likes: 4
From: Lawrenceville, GA
Originally Posted by Captain InsaneO
4.00 bore
I just want to make sure I get the correct gasket.
Thanks.
Bill
Thread Starter
Joined: Apr 2003
Posts: 2,597
Likes: 4
From: Lawrenceville, GA
Originally Posted by mr2guru
As far as copper spray goes... the best I've ever used is VHT. Way better than mr. gasket or permatex.
Thanks,
Bill
Thread Starter
Joined: Apr 2003
Posts: 2,597
Likes: 4
From: Lawrenceville, GA
Here is the info from Cometic:
H1518SP1040S is the part number you will need. They sell for $82.85 each.
Kevyn Kistner
Technical Sales
Cometic Gasket
Hope this helps someone else besides me.
Bill
H1518SP1040S is the part number you will need. They sell for $82.85 each.
Kevyn Kistner
Technical Sales
Cometic Gasket
Hope this helps someone else besides me.
Bill
Originally Posted by Bill Bowling
Here is the info from Cometic:
H1518SP1040S is the part number you will need. They sell for $82.85 each.
Kevyn Kistner
Technical Sales
Cometic Gasket
Hope this helps someone else besides me.
Bill
H1518SP1040S is the part number you will need. They sell for $82.85 each.
Kevyn Kistner
Technical Sales
Cometic Gasket
Hope this helps someone else besides me.
Bill
It's all about surface prep and the finish (RA) of the head and block. The smoother you can have the two parts the better the gaskets work for both sealing and preventing blow outs. The copper spray seems to help seal the water/oil passages as it does nothing to help with combustion sealing. I wouldn'tbe afraid to use a light coat of copper spray as insurance.
Thread Starter
Joined: Apr 2003
Posts: 2,597
Likes: 4
From: Lawrenceville, GA
Originally Posted by 405HP_Z06
What is the bore diameter on this gasket?
Bill
Originally Posted by Bill Bowling
The bore is 4.100" which is the same as the Fel Pro 1161L and 1161R which is Dart's first choice. The problem is the Fel Pro does not come in .040 thickness.
Bill
Bill
I had Cometics leak on my stock block and yes the block and heads were meticulously prepped and the gaskets were sprayed with copper spray. I'm not having any problems on the 403 with the .040 Cometics. Fingers crossed.
