1960 C10 Mystery "Blue hole"
 

On my 1960 C10 283 with 2 speed powerglide that I am restoring, there is a hole in the firewall next to the master cylinder with a light blue plastic "pipe" through it. Inner diameter is 1 and 13/16th inches, outer diameter is 2 inches. Please see photos.

Does anyone know what this is? Is there a plug that is supposed to go in there?

Re: 1960 C10 Mystery "Blue hole"
 

Looks to me like the hole for a 60-62 clutch master cylinder, if the truck was a manual transmission then I would've been equipped with a different master cylinder, for both the brakes and the clutch. I'm guessing someone swapped to an auto tranny.

Re: 1960 C10 Mystery "Blue hole"
 

Like this

Re: 1960 C10 Mystery "Blue hole"
 

Factory auto truck would've had a plug like this

Re: 1960 C10 Mystery "Blue hole"
 

that backwards bow tie is killing me!

Re: 1960 C10 Mystery "Blue hole"
 

Although I have never seen one, I was kinda thinking the same thing. However, there is no other indication that it originally had a standard. If someone changed it to an automatic, they did a very thorough job. And the 2 speed powerglide is the proper one, cast iron with no pan.

Does anyone know if there is some way to determine what it was originally built with, other than the "Blue hole"?

Re: 1960 C10 Mystery "Blue hole"
 

I know, ImpalaJim, it won't be there long!!

Re: 1960 C10 Mystery "Blue hole"
 

Awesome picture! I wonder if that plug is available somewhere. I haven't seen it in all my online travels through parts websites.

Re: 1960 C10 Mystery "Blue hole"
 

try some ceramic shops! I bet a bank stop would work.

Re: 1960 C10 Mystery "Blue hole"
 

The manual two port was not new to our trucks. My 56 Willeys Jeep had one, had to get new one and part # match to 62

Re: 1960 C10 Mystery "Blue hole"
 

This is the first time I have come across it, but I'm new at this. I wonder if the plug came out and someone plugged it with a piece of pipe and a cap.