1968 Rubber plug next to the radiator

[Ricky Knapik]

Hey everyone! Got a new one here. I've been curious about the "round plug in square hole" theory. There is a square hole on each side of the radiator that I've been wondering about. Everything I could find and have seen in person says it should be empty. Then yesterday at a local show, 2 unmolested 68's, F plant, has a plug in the holes. John Murphy shows up with his Cali, and we begin to debate this plug. I happen to have a pic of Mike Jewell's car with no plug. So, everyone run out and check their car and give some feedback. Is this just a San Jose vs Michigan thing?

 

[speedy02]

You're onto something about the difference in plants (San Jose vs Dearborn). I would like to see what others have to say about this as well.

I found the following on the Concours Mustang website. Links may require an account to access.

San Jose - Unrestored 5200-mile San Jose GT https://www.concoursmustang.com/forum/index.php?topic=2313.0

Dearborn - Unrestored T Code Dearborn https://www.concoursmustang.com/forum/index.php?topic=5365.0

 

[stangfan]

Hey everyone! Got a new one here. I've been curious about the "round plug in square hole" theory. There is a square hole on each side of the radiator that I've been wondering about. Everything I could find and have seen in person says it should be empty. Then yesterday at a local show, 2 unmolested 68's, F plant, has a plug in the holes. John Murphy shows up with his Cali, and we begin to debate this plug. I happen to have a pic of Mike Jewell's car with no plug. So, everyone run out and check their car and give some feedback. Is this just a San Jose vs Michigan thing?

Mine has the square holes with NO plugs.

 

[Mosesatm]

What’s the purpose of the square hole?

 

[Ricky Knapik]

What’s the purpose of the square hole?

That's the next good question!

 

[Ruppstang]

The same core support was use for the Cougars hidden head light covers the used a square mounting hole.

Our unrestored 68 HCS has both plugs. When I am judging I only deduct if there is no plug on the driver side. It was required there to protect the voltage regulator from water. I see the passenger side with and without plugs. Early 67 Mustangs had an oval hole and an oval grommet. That grommet is not reproduced so if you find one it is worth some $$$.

 

[Ricky Knapik]

The same core support was use for the Cougars hidden head light covers the used a square mounting hole.

Our unrestored 68 HCS has both plugs. When I am judging I only deduct if there is no plug on the driver side. It was required there to protect the voltage regulator from water. I see the passenger side with and without plugs. Early 67 Mustangs had an oval hole and an oval grommet. That grommet is not reproduced so if you find one it is worth some $$$.

Yep, saw the oval on a couple 67's yesterday. Marty, is the round one reproduced that you know of? I tried a modern 1 inch that didnt work. The part that fits through is pretty small.

 

[Ricky Knapik]

Just Talked to John Murphy. He and Marty Rupp by far are the most knowledgeable GT/CS guys I know. John found it in a shop book exactly as Marty said! The left side only regardless of build location. Part # 376966-S. NPD has it for $2.99 at all 4 of their locations! Another mystery solved!