i am removing those air tubes that comes out of the exhaust manifold of my 72 240z. i need to plug those holes. will anyone kind enough to help me figure out the size of bolt that i need to plug those six thread holes? thanks , hf

Check the Thread that you started yesterday on this subject. We've posted quite a bit on it!

http://www.240z.org/forums/showthread.php?s=&postid=28780#post28780

I just went through it .... on my header though.

The thread size for the EGR is metric ( 22x1.5 )

My header had another threaded bung it is also

metric ( 20x1.5 )

I hope i helped.

-Jeff