67 O327/300 HP Oil Drain Plug

[Kirk M.]

I own a 1967 327/300HP, PS, PB, automatic with AC. What exactly should my oil pan drain plug be to be NCRS correct (ie: markings and correct size). Thanks.

Kirk

[Joe R.]

Re: 67 O327/300 HP Oil Drain Plug

I own a 1967 327/300HP, PS, PB, automatic with AC. What exactly should my oil pan drain plug be to be NCRS correct (ie: markings and correct size). Thanks.

Kirk

Hi Kirk:

Production drain plugs were made by several different suppliers, and each supplier had a different head mark. Attached is a photo of the "circle A" headmark, but lots of other head marks have been observed on original cars. I think the drain plug on my car says "FC" or something.

Aside from the head mark, the overall size and appearance of all the original drain pugs is the same.

If you decide yours is not correct, Long Island Corvette sells a pretty good reproduction of the "circle A" version.

[Kirk M.]

Re: 67 O327/300 HP Oil Drain Plug

Thanks Joe.

It seems pretty easy to find originals. I just thought there was a size differential that I needed to be aware of. For instance, many of them advertised on Ebay say 7/8", while the JG talks about width and thickness of the head but doesn't mention thread size. Also, can you just use a modern "gasket" under the original drain plug? Don't see anything in the JG regarding the "gasket".

Kirk

[John H.]

Re: 67 O327/300 HP Oil Drain Plug

Thanks Joe.

It seems pretty easy to find originals. I just thought there was a size differential that I needed to be aware of. For instance, many of them advertised on Ebay say 7/8", while the JG talks about width and thickness of the head but doesn't mention thread size. Also, can you just use a modern "gasket" under the original drain plug? Don't see anything in the JG regarding the "gasket".

Kirk

Kirk -

All oil pan drain plugs, regardless of head configuration, have 1/2"-20 straight machine threads, and most used a plastic washer to seal the joint (unless someone stripped it at some point and used one of the Bubba thread-cutting oversize "fixit" plugs.