Intake manifold breather tube

[00fxd]

I have to bore my Edelbrock manifold for a breather tube, small block. Can anyone tell me the exact hole size? I know that some have freeze plugs in them to block them off. The freeze plugs usually have the size stamped on them. If someone could look at theirs and let me know what it says.
Thanks.

 

[G Winter]

are you talking about the filler tube at the front of the intake? If so I have an old 67 or 68 cast iron manifold in the garage. If nowone else comes back with the answer I could measure it tomorrow after work.

Glenn

 

[00fxd]

Yes Glen, Thats it. I should have called it the oil filler tube. I see that you are a machinest. Perfect. I would like to have you measure that hole.
Thanks, Frank.

 

[JohnZ]

That hole is 1.24" in diameter.

 

[G Winter]

looks like you have your answer. Pay attention to the fact that it is 1.24 not .25 you don't want that hole to big or the tube will want to come out by itself. You should have to drive it in.

Glenn

 

[00fxd]

Thanks guys 1.24 will give me an interference fit.