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Oil pan gasket install

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Old Aug 4, 2017 | 07:54 AM
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Default Oil pan gasket install

1981 C3 350

So I'm replacing my oil pan and gasket. I tried using a felpro one piece but it's too thick. It causes the pan to "rock" back and forth and not seat on both sides. It looks like the timing cover side is too thick. I went out and bought a 4 piece thin gasket but am not really sure how to install it because all the videos I can find show the engine being out and RTVing the gasket to the block. Any pics or directions would be appreciated.
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Old Aug 4, 2017 | 08:52 AM
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One piece worked great on my car....

Is it fully seated? Anything causing it to hang up?
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Old Aug 4, 2017 | 09:07 AM
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I think there are 2 versions of the one piece pan gasket. Felpro. 34510T. & 34510R. I thought one had a thinner front seal area.
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Old Aug 4, 2017 | 09:12 AM
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Correct. Over the years GM made two very different front timing cover seal thicknesses. They are not close enough to interchange.
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Old Aug 4, 2017 | 09:22 AM
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Originally Posted by speedreed8
I think there are 2 versions of the one piece pan gasket. Felpro. 34510T. & 34510R. I thought one had a thinner front seal area.
OS34510T is the one I have that's too thick
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Old Aug 4, 2017 | 09:53 AM
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Pics ( i know its all dirty, will clean before install )







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Old Aug 4, 2017 | 10:54 AM
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The thin gasket is OS34509T.
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Old Aug 4, 2017 | 11:48 AM
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One thing I remember when installing the one-piece gasket myself a few weeks ago is that it compresses a ton. It originally felt way too thick to me, but I figured out I had to put the four corner bolts in (Also I put a couple bolts on the sides to keep the pan from warping or anything) and tightened those all up to compress the gasket fully. I'm not sure what you have or if this works for you, but I thought I'd share.

Last edited by Shdggsdv; Aug 4, 2017 at 11:51 AM.
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Old Aug 4, 2017 | 06:50 PM
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Originally Posted by tehjrow
1981 C3 350

So I'm replacing my oil pan and gasket. I tried using a felpro one piece but it's too thick. It causes the pan to "rock" back and forth and not seat on both sides. It looks like the timing cover side is too thick. I went out and bought a 4 piece thin gasket but am not really sure how to install it because all the videos I can find show the engine being out and RTVing the gasket to the block. Any pics or directions would be appreciated.
I agree with Brass Pass. For less than $25 you can get a oil pan stud kit and never look back. Just snug the studs into the block with a drop of Loctite Blue using two nuts. Now all the holes in your pan gasket and pan are perfectly lined up. The studs will also hold the four piece side gaskets in place until your RTV sets up. Not much fun lying on your back with a pan in one hand and a bolt in the other is it?
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Old Aug 4, 2017 | 09:29 PM
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Originally Posted by tehjrow
1981 C3 350

So I'm replacing my oil pan and gasket. I tried using a felpro one piece but it's too thick. It causes the pan to "rock" back and forth and not seat on both sides.


Just so you know you're not the first to experience this. I ended up using a 4 piece.

















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Old Aug 4, 2017 | 10:05 PM
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That last picture is a great comparison between the thick and thin gaskets!!
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Old Aug 5, 2017 | 07:11 AM
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Does the front of the gasket compress that much? that is one huge gap at the sides of the oil pan?
Did the make a gasket that thick so that you don't have to put so much rtv on there?
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Old Aug 5, 2017 | 08:03 AM
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Originally Posted by Primož Krajcar
Does the front of the gasket compress that much? that is one huge gap at the sides of the oil pan?
Did they make a gasket that thick so that you don't have to put so much rtv on there?
NO.........they "made it that thick", because as mentioned several times in this thread, there are two different generations of that gasket, as designed by Chevrolet engineers.
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Old Aug 5, 2017 | 01:31 PM
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Ended up using a 4 piece and got her back together. No more oil leak! Now she runs like **** (but she did before), time to hunt for my vacuum leak...
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