What is this?

[KMAYK5]

Can anyone help me figure out what this port is for? I'm trying to find a plug for it but I'm not having any luck.

I believe it is some kind of vacuum port for emissions crap but I cant figure out the thread pitch. It's in-between 1/2 and 3/4in.

In this picture it is just to the right of the thermostat housing.

Any help would be appreciated. I'm hoping to get the cam broken in this weekend but won't be able to until I figure out what this is.

 

[imiceman44]

Can anyone help me figure out what this port is for? I'm trying to find a plug for it but I'm not having any luck.

I believe it is some kind of vacuum port for emissions crap but I cant figure out the thread pitch. It's in-between 1/2 and 3/4in.

In this picture it is just to the right of the thermostat housing.

Any help would be appreciated. I'm hoping to get the cam broken in this weekend but won't be able to until I figure out what this is.

It's for a vacuum switch.

 

[KMAYK5]

So if I call the parts store and ask for a vacuum switch will they be able to get the right one?

What I'm trying to ask are all the threads the same?

 

[nvrenuf]

All threads are not the same.

My guess based on the machined surface around the hole is that whatever sensor belongs there will have a brass washer or similar to seal. Imo, that does NOT look like a hole for a pipe threaded sensor or fitting as they typically are unfinished around the hole.

 

[imiceman44]

All threads are not the same.

My guess based on the machined surface around the hole is that whatever sensor belongs there will have a brass washer or similar to seal. Imo, that does NOT look like a hole for a pipe threaded sensor or fitting as they typically are unfinished around the hole.

Those vacuum switches are heat activated and have a probe sticking in the coolant and do have a brass or aluminum washer to seal the coolant in.
I could be wrong since this is an aftermarket intake but if it's a replacement intake then it would have the same provisions.

 

[KMAYK5]

Sorry. I failed to mention that this is a carb intake for vortec heads. I found this picture that may help.

 

[1BEATK5]

so its the egr tube. which in the first picture looks like its flair to me.

 

[sweetk30]

thats the egr tube port for 96-2000 vortec motors.

 

[ssyork]

I ran into the same problem with my vortec heads. I cut the tube apart to get the fitting and then welded it up on the inside to make a plug.
edit- I found a plug for the intake side, was a pipe plug I had laying around, I welded up the exhaust side. I can pull it out and measure it tonight if you want.

 

[KMAYK5]

Awesome thanks guys. Its easy to figure out what i need when i know what the damn things called lol

Apparently they are the same as a 10AN fitting which has a 7/8-15 thread so those will work too.

 

[KMAYK5]

I ran into the same problem with my vortec heads. I cut the tube apart to get the fitting and then welded it up on the inside to make a plug.
edit- I found a plug for the intake side, was a pipe plug I had laying around, I welded up the exhaust side. I can pull it out and measure it tonight if you want.

I appreciate the offer but I got it figured out. I have one ordered and on the way.