Head gaskets

[Asylum]

Well now that 60* has totally messed up the head gasket issue, and GM wants you to buy a whole kit rather than just the actual head gaskets I need, what is everyone using?

Fel pro?

[3X00-Modified]

Bull crap.

I just bought two.

Then again thats for a 3400... You may be screwed with the 3500. You should check the bore though, maybe a 3400 gasket would work for you and up your compression a bit since the fire ring IIRC should still be larger than the 3500 bore. It says on WOT-Tech that stock 3400 gaskets are 3.750, and that you need 3.720 to clear the head combustion chamber, and 3500 bore is listed as 3.70... So you should be able to get away with two 3400 headgaskets.

STAY AWAY from felpro, they are not a graphite material and have always fallen apart on me.

This the number they gave you?

GM #12594816 If so then yeah that's a kit, and the only thing avilable for the 3500.. It says 3.9L as well so thats confusing.

[Asylum]

Damn Cometic.

So now I am going to have to but the whole GM kit and have even more crap I don't need laying around.

This is starting to upset me, and I don't upset well!

[3X00-Modified]

Return the lower set you bought if thats what your talking about when it comes to crap laying around.

If I hadn't bought one already I would buy the LIMG from you... But I'm set on those.

[Asylum]

That is scary. It IS listed for both the 3500 and 3900!!

[Asylum]

So you are suggesting the 3400 GM gasket would work?

They better be absolutely perfect!

Got a part number?

Thanx

[3X00-Modified]

I can't see why they wouldn't work. I use them with 3500 heads and they clear the combustion chamber, and supply the head with all the proper cooling.

If you have a set of old 3500 gaskets lying around I would definately compare them first, or if you have a 3500 and 3400 block nearby compare the cooling jackets to make sure the holes should/would be in the same spot.

I just bought two of these #12589907 for $28 each. Not too shabby.

But my assumption here is going with a 3.750 diameter gasket it should fit perfectly fine on a 3.70 bore engine, and should increase your compression just a bit since your using a smaller diameter gasket... 9.79 to 9.83 according to the CR Calculator.

I'm also thinking if they say to use a MLS gasket with a bore of 3.72 for the 3500, and a stock 3400 gasket is 3.750, I would think your all set.




I have a 3500 block at my parents house and I have a set of these gaskets, do you want me to see if they fit good? I can do that and take pics for you tonight if you wish.

[1988GTU]

If you want to sell your LIMG set PM me, I may have a use for it. Also, post the part number of it and where you bought it. It will just save me some time thinking.

[Asylum]

OK. I spoke with Rodney over a couple of Molsons this afternoon, examined all the numbers, and again, Jon is right on!

I'm going to order the 3400 GM gaskets and see just how close it is.

Thanx!

[Asylum]

If you want to sell your LIMG set PM me, I may have a use for it. Also, post the part number of it and where you bought it. It will just save me some time thinking.

If I can use the 3400 gaskets I'll be needing this stuff.

If not and I have to order a complete 3500 set, I will let you know.

[3X00-Modified]

Holy hell its friken close! Top of the bores are chamfered out, check EVERYTHING to be sure the pistons do not hit the fire ring. All the coolant passages are the same as a 3400.

Part number









If you need better pics I'll get the real camera and not the Phone

[1988GTU]

If you want to sell your LIMG set PM me, I may have a use for it. Also, post the part number of it and where you bought it. It will just save me some time thinking.

If I can use the 3400 gaskets I'll be needing this stuff.

If not and I have to order a complete 3500 set, I will let you know.

[Asylum]

WOW!

That is friggen tight!

What the hell would the 3.720" MLS gaskets look like? (I'm thinking that whole idea is FUBBARED!)

If the 3400's were perfect!! they would work, but tolerences are??

Maybe just a little filing would do it, but it's alot of work if it messes up!

I'm guessing that chamfer is there for a reason.

[3X00-Modified]

Yeah I'm not worried on the 3.72's since I do have a 3400 bore but with the 3500 block damn that's gonna be close.

But we don't have to worry about that for a while.

I think the chamfer is to start the rings when installing the pistons... I think the 3400's have it too I didn't check tho.

[Money pit Beretta]

Sticky? There is some very good info here.