Please Identify this Oil Pan Plug
Is there any chance this is a correct part for my 1966 L-72. I am thinking not. If not any thoughts on what it is from would be appreciated. The head is 7/8". Thanks.
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Last edited by Larry T.; September 17, 2009, 10:13 PM. -
Re: Please Identify this Oil Pan Plug
I think the head should measure 7/8" across. Typical markings are an "A" or "FC" and others inside a circle. -
Re: Please Identify this Oil Pan Plug
I've seen five variations on oil pan bolt headmarks:
A, Circle-A, F-C, L, and TR
If memory serves, the F-C version is mentioned as being among those correct/original in one or more of the early C1 JG books...Comment
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Re: Please Identify this Oil Pan Plug
Larry-----
This fascination with oil pan drain bolt headmarkings never ceases to amaze me. Keep this in mind: during the 50's and 60's these oil pan plugs were being used in HUGE numbers. The GM #3779764, used for 1961 to 1967 was used not just on Chevrolets, but on all other GM car lines as well. Undoubtedly, multiple manufacturers were supplying these things by the MILLIONS and that's the reason for the various head marks.
Of course, it may be that certain manufacturers predominated during certain certain periods within the 1961-67 time frame. However, "predominated" does not mean "exclusively supplied" and I'm sure there were more than one manufacture supplying these things at any given time. So, to my thinking and with a few caveats described below, there's no way that anyone could say that a period-correct headmarking found on one of these is not original to the car. In general, I would assume that a plug with a period-correct headmarking and configuration was original to the car unless there was some good reason to suspect that it were not original (i.e. obviously replaced oil pan, etc.).
Now the caveats:
1) If someone could show that the manufacturer represented by, for example, the "F-C" headmarking was out-of-business or not supplying oil pan plugs by the time your car, or any particular car, was built, then, obviously, an oil pan plug with such a headmarking could not have been originally used on that car. No one has yet shown this as far as I am aware;
2) There were 3 similar but somehow different oil pan plugs used over the 1955-67 period, although all are functionally interchangeable. 1955-56 used GM #839079. 1957-61 used GM #3739264. 1962-67 used GM #3779764. I do not know what the differences were among these plugs, but a slight difference in across-the-flats size MAY have been one of them. In any event, if someone could show that the plug on your car was not a GM #3779764 but was, in fact, a GM #839079 or a 3739264, then it could be said unequivocally that it is not original to the car.
Barring either of the above occurring, I would opine that the plug is original to the car.In Appreciation of John HinckleyComment
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Re: Please Identify this Oil Pan Plug
I will go with that and keep my bolt. Thanks,
LarryComment
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Re: Please Identify this Oil Pan Plug
As chance would have it, I bought an oil pan today that was said to be from a 64. The drain plug was marked F-C. I would say you're good with what you have.Comment
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