67 L-79 Oil Drain plug

[Lawrence S.]

I looked in the Technical Info and judging guide for the specs on the above and it states that the plug is supposed to be 3/4" across the flats, that I can understand, further it states that the plug's thickness is 1/8" Is this correct? This seems very thin. If so can someone post a picture?

Was there a Corvette application where the oil drain plug was 11/16" across the flats?

Thanks

[Keith B.]

Re: 67 L-79 Oil Drain plug

it should be 7/8 hex head plug. they were used on all kinds of other GM engine oil pans

[Lawrence S.]

Re: 67 L-79 Oil Drain plug

Thanks Keith

[Lawrence S.]

Re: 67 L-79 Oil Drain plug

Keith,

I just checked the judging guide again and it says that the oil drain plug is 3/4" across the flats not 7/8". What is correct, anybody?

[Wayne M.]

Re: 67 L-79 Oil Drain plug

Keith,

I just checked the judging guide again and it says that the oil drain plug is 3/4" across the flats not 7/8". What is correct, anybody?

Seems that all the C2 manuals just copied one another on this one (can't speak for the most recent '63/4 and the new '66).

It's 7/8" but I'd say a tad thicker than just an eighth. Ignore the magnet tip; this was a later iteration on some engines, I believe. Also circle 'A' headmark is one of several typicals.

[Terry M.]

Re: 67 L-79 Oil Drain plug

Wow Wayne. That is a great picture. One can see the radial lines from the hot heading operation that formed the hex, and the sheer mark halfway down the hex from the sheering operation to size the hex. Nice detail.

[John H.]

Re: 67 L-79 Oil Drain plug

I looked in the Technical Info and judging guide for the specs on the above and it states that the plug is supposed to be 3/4" across the flats, that I can understand, further it states that the plug's thickness is 1/8" Is this correct?

Larry -

You must not have the latest edition of the JG - that item was revised five years ago, in the second printing of the fourth edition in 2005, as 7/8" across the flats and 1/4" thick.

[Lawrence S.]

Re: 67 L-79 Oil Drain plug

Hi John,

Yes you are right. I bought the JG in 2004 when I started my resto.

Thanks,

Lawrence

[Gary S.]

Re: 67 L-79 Oil Drain plug

Measurement