From searches, it looks like I'll need a 22mm drain plug to block off the AIR ports on the manifold. Apparently a 22mm plug only has a "sufficient" fit.

Is this hole in the manifold actually a pipe thread? Looks like it may be about a 1/2"-NPT?

I'm hoping it is, because, one, I'll get the best fit, and two, I can easily get a pipe plug from work.

 

No, an SAE plug won't fit, or at least didn't fit mine. I had to have the M22. Pipe plugs are tapered...the hole you're trying to plug isn't.

 

I used M22

 

On my brothers Impalla we took the pipe out of the manifold and welded the plug shut and put the stock piece back in. Works better than trying to find a plug that fits IMO

 

I needed an M22. I also put a bunch of copper RTV around the threads to ensure no leaks.

 

Anyone, what exactly is a M22 ?? as im going to be deleting my AIR also very soon as i just got some race version LT's..thanks

 

M22 is the reference to the METRIC threaded plug that is required to cap the A.I.R. hole in your manifold. You can find them at your local AUTOPARTS CHAINS, like Advance Auto, and so on. They are usually in their OIL DRAIN PLUG section. Less than $5.00 each. HTH's

 

what i figured, thanks a lot, gonna have to pick one up

:edit: gonna have to pick two up,lol

 

Get 2.. there are 2 holes.. one on each header/manifold..