New head with unknown port near back of head

-
cudajim

cudajim

cudajim
Joined
Jan 17, 2006
Messages
1,486
Reaction score
102
Location
Grass Valley, Ca.
I acquired a rebuild head which seems to be 1975 vintage so it's a newer style. I was hoping to install it onto my 67 225 6-banger but I noticed an extra port at the back of the head. Can anybody tell me what this is and how do I plug it? See the images below.
head (3).jpg
port (1).jpg
port (2).jpg
 
It's for the air injection system for emissions. You can make a flat plate to cover it, and use the bolt hole right there, or tap it and install a plug, or use a small "freeze" plug. There should be the correct gasket in the gasket set.
 
Charrlie_S said:
It's for the air injection system for emissions. You can make a flat plate to cover it, and use the bolt hole right there, or tap it and install a plug, or use a small "freeze" plug. There should be the correct gasket in the gasket set.
Click to expand...
I'll get creative with it tomorrow. I assume then if I don't plug it exhaust will come blasting out?
 
I made a 3/16 plate for mine and cut a gasket out of heavy duty steel impregnated gasket material. I said impregnated. heh heh heh huh huh huh. But the freeze plug idea will work great too.
 
Ok so I made a little plate, glued it on with hi-temp RTV and used the bolt to hold it. It works just fine and looks good too after I painted it. I also had to plug a water outlet on the top of the head, I think it was 3/8 fine thread.
 
Probably 1/8 NPT (pipe thread)
Close to 3/8 actual diameter and pretty fine thread
 
You must log in or register to reply here.
-

Back
Top