Guys, Can I tap cast iron exhaust manifold to add a air inlet into the manifold at one point and do I have to do anything special like heli-coil to account for the different metals and high temperature? I've see OEM's do it but not sure if they do anything special or have inserts or something. I have a small section of tube that I need to add prior to the check valve but need some help here. I might just add it in the exhaust tube but I want it to look good, and pass the visual. OEM units have one for each port but I'm going to try and add it and get it to pass...will see!
Later

The holes in my manifolds for the air injection rails don't have heli coils, just tapped holes in the cast.....

I'll sell you these for $50.00 plus shipping. Email me. :D

http://www.directcon.net/kurtz/350_manifolds.jpg

That was actually me SweetCJ7. Email me.... not the wife. :D

I have center dumps....but thanks anyway....

Don't see why not, lots of guys (myself included) drill and tap diesel manifolds for pyros.

Pete