Recommend a Head Gasket
Thread Starter
Safety Car
Joined: Jul 1999
Posts: 3,946
Likes: 63
From: Marianna FL
Recommend a Head Gasket
383 LT4, AFR 210's, 9:1 compression, 14 PSI boost, alcohol injection. What would you use? Right now, I'm leaning toward Fel Pro MLS gaskets if they make an LTx application.
Racer
Joined: Nov 2002
Posts: 427
Likes: 0
From: Stillwater OK, Fun City USA
The rivets that hold the gasket together also interfer with the AFR head deck and will not allow them to seat completely, so make sure to cut reliefs in the heads.
Drifting
Joined: Aug 2001
Posts: 1,500
Likes: 0
From: Holliston MA
Cruise-In VII Veteran
I just bought a set of the Fel Pro MLS's. Been using the Cometics for years now. The coating on the Fel Pro's are actually tacky. Just looking at them out of the package I like them. They will pick up dust and dirt so be careful in handling them.
With the Cometics I've always used a sealer (spray copper) on them contary to what Cometic recommends and have never had any sealing issues with them. The sealer makes up for minor surface irregularities in the machine work. Without the sealer the surface needs to be smooth almost to the point that you can't feel scratches with a finger nail.
Instructor
Joined: Oct 2004
Posts: 247
Likes: 0
From: Montanja Noord Aruba
Well....I've been using Cometics and no complain. The last time I rebuilded the engine, they sent me a wrong set of gasket. I did use the old one and no problemo...600+rwhp with boost and juice and the old Cometics did the job.
Melting Slicks
Joined: Jan 2002
Posts: 3,293
Likes: 79
From: Jackson MI
Cometic is the way to go if you have a freshly surfaced deck and head.
If you are replacing a blown head gasket Felpro makes a performance head gasket that has been holding up for me just fine.
If you are replacing a blown head gasket Felpro makes a performance head gasket that has been holding up for me just fine.
Thread Starter
Safety Car
Joined: Jul 1999
Posts: 3,946
Likes: 63
From: Marianna FL
Some local folks seem to have trouble with the Cometics leaking. I was planning to stay away from them if possible. I do have studs and plan to retorque after breaking the engine in. Thanks for all the info. 
Pro
Joined: Aug 2004
Posts: 544
Likes: 0
I have Cometics and a leak... I had the combustion chambers coated and I think that is my problem. No compression leak, but I have an oil leak that starts at the oil drainback holes and goes to the rear of the motor. No fun.
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Le Mans Master
Joined: Jan 2003
Posts: 8,596
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From: Portland Oregon
Your block and head surfaces has to be cut on a CBN machine rather than an old style surface grinder. If you have or had it cut on a old machine I wouldn't bother attempting to use the MLS gaskets. I had a engine prepped on a old style machine and the damn thing leaked, basically it will seep oil. I am using a set of LT4 GM composite gasket with studs making 12 to 14 PSI and have not experienced any issues. They key to making this work is to avoid any detonation, if you do that with a good tune a standard composite gasket or even a Fel-Pro 1074 will work fine as long as studs are used. If you attempt to use the MLS, and in the case of the LTx engines it will have to be either Mr Gasket or Cometic, and be advised that Cometic makes Mr Gaskets MLS gaskets in one flavor that being said they are made as a .040 thick gasket, and in both cases you will need to remove the rivets for clearance or notch the heads. I suggest removing the rivets and coating them with copper coat.
Safety Car
Joined: Apr 2001
Posts: 3,525
Likes: 2
From: Houston TX
I have used the Cometics with copper coating for many years in boosted applications with no issues. Even turning the boost up has not caused an issue, to date. (knocking on wood)
But, I think one thing that is helping is that the block and heads were prepared for MLS type of gasket, And the AFR heads have the extra thick deck, which helps keep them seated.
Aaron
But, I think one thing that is helping is that the block and heads were prepared for MLS type of gasket, And the AFR heads have the extra thick deck, which helps keep them seated.
Aaron
