BBC Head Gasket Question

This doesnt look right? This is my 396 BBC with Cometic head gaskets, I am ready to put the cylinder heads on today but it looks like one of the coolant holes is partially blocked by the head gasket? Do I have the right head gasket?

 

Bump back up......

Here is another pic....this is my concern, this channel is recessed on the backside of this gasket as well and looks like it would allow water to pass between the block and gasket.

 

Is this a composition gasket of just a steel shim type? I don't like the steel shim type, it's old technology and hasn't been used for a while. I like the Fel Pro Blue Perma-torque type (sandwich style). I'm unfamiliar with the kind you have pictured and the partially covered hole would concern me also. I'm sure someone with more up to date information will chime in.

Frank

 

Are you sure the gaskets are for a Gen IV BB? The cooling passages for the later BB engines are different. I discovered this when putting Edel Aluminum heads on a 396. Had to do some drilling on the block.

 

Gotta part #?

 

Cometic part number is H1173spab04 that part doesnt show up on their site.

Wierd thing is the gasket does have the proper holes on the upper ends so it appears I have the right generation of block.

 

I think those are gaskets so you can run gen5 heads on mark 5 block. ??. Or vice verse???

 

mark IV and gen V headsd are interchangeable. So I would assume so are the Gaskets. Gen VI blockes are different Im not exactly sure how but they require a "special Gasket to install an older head or a Gen VI vortec head on and older mark IV or gen V block. those maybe the newer Gen VI gaskets

 

Those are not the correct head gaskets for a 396. I know cause I am running one in my 40 chevy truck. They aren't even close. I agree with fab 32 use the fel-pro gaskets.

 

The genIV blocks have way bigger water ports between the cylnders. I think. The raised part of the head gasket are the size of the ports on the genIV block. I believe you have the Gen IV gasket. I think you can put genIV heads on markIV blocks but not the other way around. It has to do with these water jackets. I fought this a few years ago but I can't remember the whole story.

 

every hole is spot on except this one water jacket. They are specifically marked hevy BB 396,402,427,454

Thanks for the replies, I will call them tomorrow and let you guys know the answer.

 

Its just a defect. Cut it out a little more and run it. Use a rat tail file.No big deal. Mikey

 

I like the FelPro head gaskets too.

I wonder if yours are really more for racing, where you might tear the engine down after a racing season? If you just want some good reliable gaskets, you might want to use some FelPro gaskets instead. I've always had good luck with FelPro gaskets. The times I can remember when I had to tear down an engine to replace a blown head gasket, the old head gaskets looked like your bare metal ones.

 

How does the hole line up on the head?

 

been out of the loop for a while haven't you. MLS and cometics are the greatest thing in head gaskets since sliced bread. Us turbo guys are using the crap out of them with fantastic sucess.

Here is mine. These are the FlePro MLS gaskets and they block a different part of the water port. No heating problems at all.





http://www.theturboforums.com/smf/index.php?topic=97438.0

Glen, I'm not sure what would happen in your case. Like the others said, check against the head. Most of the modern gaskets I have been dealing with lately are modifying the port alignment for better cooling. Contact Cometic with these pictures also.

 

Glen, I just posted this thread over on the the turbo forum in the GM section. Let's see what they know about that chanel thingy.

 

It lines up on the head perfect. Again, its not so much the blockage I worry about, its that little channel that looks like it would allow water to pass between the block and gasket.

Thanks Steve, I should be able to call Cometic in an hour or so.

 

Robert from The Turbo Forums says:

 

The walls have ATF fluid on them, it just looks funny from the flash.
He said the channel might be to help with different hole locations on blocks.

Cometic said it would squish and seal....I ordered a set of fel pro MLS from Robert at the
turbo site......but Fel Pro only has a 4.250 and I have a 4.155 hole, Im going to compare the two and decide.

Thanks for your help.

 

I got the gasket thing figured out and got the heads torqued down. I just sat the intake on to sneak a picture.
Now I have to figure out my pushrod length.





funny how small a 750 carb looks on these.

 

Call Or E mail Mark @ Flatout gaskets.
Mark & his gang ran F pro before they sold out.

396 - Ah memories...!
Did you have the wall thickness of all the cylinders checked...??
The 96's had some core shift problems.

 

we run a donovan block with 4.600 bore and have had water holes off a little also.a little work with the file and put a dab of silicone around each of them and at the top corners at each end.we spray 500 hp in ours, and cometics hold up better than fel pro and are reusable 2-4 times.