Small Block Oil Pan Gaskets

[Joe L.]

A recent question regarding the subject inspired me to provide a little more information.

First of all, I'm going to be talking about gasket SETS. Gasket sets are peculiar to SERVICE since gaskets sets were not used in PRODUCTION. In PRODUCTION the components of the SERVICE sets were called out and used according to their individual part numbers. However, these same components were usually used to make up the SERVICE gasket sets. Incidentally, the components of the gasket sets were also available separately in SERVICE but these were rarely purchased since in virtually all cases, anyone servicing an engine would need the complete set and not a single component of the set.

In 1968 oil pan gasket set GM #3931597 was released for SERVICE. It replaced several earlier part numbers going back to 1955 and continued to SERVICE all 1955 and later Corvette small block applications right through 1974. It was finally replaced in July, 1980 by set GM #14002201 and in June, 1984 the latter was replaced by GM #14079400. It was finally discontinued without supercession about 2 years ago.

The end seals in all of the above are identical and the front seal is of 0.22" thickness. However, the side rail gaskets differ. The 3931597 used some sort of composition gasket of dark gray material. This type of gasket was used for many gasketing applications in days of old. This type of gasket is usually a real bitch to remove, often requiring gasket remover or a wire wheel to completely clean the surface. And, usually, if one does not get a scrupulously clean surface, there will be a leak after new gaskets are installed.

The GM #14002201 included side rail gaskets of some sort of light gray apparently cellulosic material. I don't know much about these gaskets.

The GM #14079400 included side rail gaskets of rubberized cork with a steel core. In my opinion, these were the best of the side rail gaskets ever released for 4 piece gasket type applications. The same type side rail gaskets were used for 1975+ small block applications right up until the time that GM went to a one piece gasket in 1986. The only difference was a right side dipstick on most applications after 1979.

I should also mention that when used on an engine restoration it does not really matter what type of side rail gaskets are used. Inasmuch as all 1955-79 Corvette engines were painted as an assembly, the edge of the side rail gaskets is painted engine color so no one will ever know the difference.

As I've mentioned many times, I will not use a 4 piece type oil pan gasket again. For me, the one piece silicone rubber gaskets are the ONLY way to go. As I've also said many times before, GM did not go to the one piece type gasket in 1986 because the 4 piece type worked just as well.


Below are some photos of the side rail gaskets included with the 3931597 and 14079400 gasket sets. If you look real carefully at the side view of the 14079400 gasket you will note the steel core.

DSCN3662.jpgDSCN3658.jpgDSCN3659.jpgDSCN3661.jpg

[Harry S.]

Re: Small Block Oil Pan Gaskets

Joe, Great information. Thank you

I found an unopened set last week. Lots of goodies in the package I did not expect.

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[Joe L.]

Re: Small Block Oil Pan Gaskets

Joe, Great information. Thank you

I found an unopened set last week. Lots of goodies in the package I did not expect.

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Harry------


Yes, most oil pan gasket sets include the exhaust gaskets and packings. However, the 14079400 also includes a bonus most others do not. That is the 2 rings (in your case, in the yellow package). These are used in place of the asbestos fiber "donut" packings for some applications, mostly truck. They were never originally used for Corvette applications. However, they are the only thing I will use. These are made of sintered iron. They will not deteriorate in use, causing loosening and exhaust leaks. They were GM #3731062 but are now discontinued without supercession.

By the way, all of the GM oil pan gasket sets I know of only contained the exhaust gaskets and packings for 2" systems. For 2-1/2" systems the included gaskets and packings were useless and the necessary gaskets and packings had to be purchased separately.

[Ron G.]

Re: Small Block Oil Pan Gaskets

I just purchased two sets of new old stock oil pan gasket sets, part number 3931597 in un-open packages back from the early 1970s. Apparently they still look brand new and well preserved. I just have a penchant for First design NOS parts.

[Joe L.]

Re: Small Block Oil Pan Gaskets

I just have a penchant for First design NOS parts.

Ron------


Yes, me too. However, my interest now is primarily for historical, reference and "parts preservation" purposes rather than actually intending to use most of them.

By the way, as far as 1968-74 goes, the 3931597 are the original design. But, as I mentioned, they would not be original design for earlier small blocks for which the 3931597 was SERVICE until 1980.

One more thing: for parts like these oil pan gaskets it's possible that every set of a particular part number might not contain the exact same type side gaskets. That's because GM was using millions of these parts in any given year. So, they probably had multiple gasket manufacturing sources. Each one may have used different materials to achieve the same GM spec. or they might have been the same materials but differently colored. I highly doubt there was a GM spec for color of these gaskets but it is possible there was a GM spec for a specific material.

[Ron G.]