64 SB oil pan plug

**Joe L.** · December 11, 2009, 10:51 PM

Re: 64 SB oil pan plug

Originally posted by Don Meluzio (30768)

I know that a TR fastener is the typical oil pan plug. Mine is a Large A with a 0 around it. I believe that is American screw products. Although not typical , could that be acceptable for correctness in judging standards. it is a 64 small block.

Don-----

In my opinion, I believe the A in a circle is a period correct headmark. The only way to know which headmark was originally installed on your car is to have the original plug.

**Wayne M.** · December 12, 2009, 09:10 AM

Re: 64 SB oil pan plug

Originally posted by Don Meluzio (30768)

I know that a TR fastener is the typical oil pan plug. Mine is a Large A with a 0 around it. I believe that is American screw products. Although not typical , could that be acceptable for correctness in judging standards. it is a 64 small block.

Here's another variant (with a magnetic tip) although I don't know if it was ever a C2 production item. Notice the 3 punch dots in a triangular arrangement, which the original does not have.

Also, the head hex size is 7/8", and not 3/4" as appears (ed ?) in some C2 TIM&JG's. Head thickness is 1/4" on this one. I see the '65 guide calls for 1/8" thick, which seems to be inviting trouble. I'll have to look under my car to check and compare head thickness with what's there now.

**Michael H.** · December 12, 2009, 09:40 AM

Re: 64 SB oil pan plug

Originally posted by Wayne Midkiff (3437)

Here's another variant (with a magnetic tip) although I don't know if it was ever a C2 production item.

That would be the magnetic plug shown in a 1966 parts book for at least 65 and 66 big blocks. (possibly later?) I'll look in the book later.

**John D.** · December 12, 2009, 01:33 PM

Re: 64 SB oil pan plug

My 63 FI car has an original oil pan plug. "A" with the circle. Buttt I get dinged for having the wrong plug.
You see the 5th edition states another logo. Can't believe the judges deduct for this though as there were at least 3 different plugs used.
But I got dinged at 2 regionals for having the "A" plug. Nice master judges would like to see "M".
By the way Long Island Corvette makes an excellent dead nuts "A" with a circle pan plug. And it's very cheap.
Meanwhile those "M" plugs must be really rare. You never see them.
I was gonna add they must only be on Augusta cars but am afraid to.

**Michael H.** · December 12, 2009, 01:44 PM

Re: 64 SB oil pan plug

Originally posted by John DeGregory (2855)

"A" with the circle. Buttt I get dinged for having the wrong plug.
You see the 5th edition states another logo. .

I don't remember for sure but I thought the JG states that "A is one of the logos" possible? Or does it state that A is the ONLY logo? I doubt it.

**Don M.** · December 12, 2009, 02:12 PM

Re: 64 SB oil pan plug

thanks for all the response and the photo, I will take a look at mine tomorrow,(my car isn't home)

**Joe R.** · December 12, 2009, 05:52 PM

Re: 64 SB oil pan plug

Well I have seen many plugs on 63 thru 67 and they run the gammut. They are all the 13/16" but they are AP,M,A's and TR's. These plugs were supplied by many vendors and as we know and I preach daily, GM did not stop the line for a $0.15 plug. And yes I know they were installed at Flint.

All the 63's that I have owned (5) from SN in the 8000 to 19000 were AP's and one TR. I have no reason to believe they were ever changed.

JD you should feel good as I was told in 93 at the National Meet that my plug was wrong. Told it should be a 9/16" cause the judge had one.

And the team leader backed up his judge. Don't blame him for that either! They gotta at least act like they know what they are doing.

JR

**Michael H.** · December 12, 2009, 06:09 PM

Re: 64 SB oil pan plug

Originally posted by Michael Hanson (4067)

I don't remember for sure but I thought the JG states that "A is one of the logos" possible? Or does it state that A is the ONLY logo? I doubt it.

I take it back. I just looked and the 63-64 JG states that the drain plug has a 3/4" hex and the head marking is "M". Comments?

**Bob J.** · December 12, 2009, 07:13 PM

Re: 64 SB oil pan plug

[quote=Michael Hanson (4067);458381]I take it back. I just looked and the 63-64 JG states that the drain plug has a 3/4" hex and the head marking is "M". Comments?[/quote

I think saying it can only be M is a mistake. Bob

**John H.** · December 12, 2009, 07:14 PM

Re: 64 SB oil pan plug

Originally posted by Michael Hanson (4067)

I take it back. I just looked and the 63-64 JG states that the drain plug has a 3/4" hex and the head marking is "M". Comments?

In a word, Hogwash. It's a 7/8" hex, about 1/4" thick, and there were at least three different headmarks (TR, circle-A, L, and others). Between Flint V-8 and Tonawanda, they used 11,000 of these plugs every single day - does anyone really think they bought them all from the same supplier? Another myth persists.....

**Michael H.** · December 12, 2009, 07:26 PM

Re: 64 SB oil pan plug

Originally posted by John Hinckley (29964)

In a word, Hogwash. It's a 7/8" hex,

I guess that would be another way of putting it.

(I'm not allowed to say that kinda stuff here though)

I agree. It's a 7/8".

**Michael H.** · December 12, 2009, 07:29 PM

Re: 64 SB oil pan plug

[quote=Bob Jorjorian (1619);458399]

Originally posted by Michael Hanson (4067)

I take it back. I just looked and the 63-64 JG states that the drain plug has a 3/4" hex and the head marking is "M". Comments?[/quote

I think saying it can only be M is a mistake. Bob

Yup, definitely more than just one source for these plugs. The M was just one of them.

**Joe C.** · December 12, 2009, 09:23 PM

Re: 64 SB oil pan plug

Now that the original question has been answered, does anybody know whether or not these plugs had magnetic inner ends?

I have seen some (all with the circle-A) advertised as "correct big block magnetized", and "correct small block not magnetized". That makes no sense to me. I would think that they were all either one way or the other.

**Michael H.** · December 12, 2009, 10:05 PM

Re: 64 SB oil pan plug

Originally posted by Joe Ciaravino (32899)

Now that the original question has been answered, does anybody know whether or not these plugs had magnetic inner ends?

I have seen some (all with the circle-A) advertised as "correct big block magnetized", and "correct small block not magnetized". That makes no sense to me. I would think that they were all either one way or the other.

As I mentioned in a previous post, a 1966 printing of the parts book does specifically call out a magnetic plug for 65-66 396/427 AND 65 w/Sp. H/Perf, fuel injection. (???) (gr 1.453, part number 3866916 and described as megnatic)

There's also a part number for a standard/non magnetic plug and listed as "ALL Corvette 3779764.

The listing changes slightly in a 1969 printing but still basically calls for the same 3866916 magnetic plug for 65-66 396/427 and Sp. H/Perf., FI. 327.

And..... there's another (called a plug, part number 3866766) that is described as magnetic and shows ALL for application. Most likely the one that was sold over the counter. Many dealer parts dept's had these on a card hanging on a wall in plain view for customers.

Take your pick.