Installing headers and have a question.

I am installing some headers on my '95 Z28 and have a question about the A.I.R. fitting. What size are the threads on this thing? The fitting is too small for the new headers.

http://i323.photobucket.com/albums/nn475/slimjim_350/AIRFitting.jpg

Thanks for the help.

The single-cat exhaust manifolds used a large thread that was roughly equivalent to an M22-1.5 oil drain plug. The dual-cat (CA Emissions A4's) manifold used a smaller thread that was closer to an M18. That's what people use to plug the holes. Sounds like the holes in your headers must be the larger M22's. Are the holes in the headers about 7/8" in diameter?

Yes they are almost exactly 7/8".
My car has the single cat exhaust. The headers are Pacesetter mids 70-1335, if that helps. I emailed them, but I haven't heard back from them yet.

Do you still have your old AIR fittings? Do they screw into the headers?

If so, just go to the hardware store and screw them into something there that fits. Then you know the size. :)

Do you still have your old AIR fittings? Do they screw into the headers?
Yes, I do.:) No they won't.:(

If so, just go to the hardware store and screw them into something there that fits. Then you know the size. :)
I'll have to do that tomorrow, maybe I'll get lucky.

Me and my buddy went on EBAY and ordered 2 sets from a guy in Arizona and they were m22 x 1.5 .Cost was 9.95 ea.and i also used a small copper plug and sealer and the plugs fit fine,i could not find anything locally:no:

There's a place in Canada sells the M22 oil drain plugs for less than $2 each. They are also available from Dodge dealers, since the Cummins Diesel used in the Dodge trucks has an M22 drain plug. But he's saying the STOCK pieces will not thread into the Pacesetter headers either, so that would sort of rule out M22's.

http://www.cgenterprises.com/drain_plugs_metric.htm

Well, one step closer anyway.:)
To my surprise, the non-flared end isn't metric but is 3/4"-16 machine thread. The flared end is not a big deal, yet. I think it's just a standard flare fitting anyway.

Are the holes in the headers about 7/8" in diameter?
As a matter of fact those fittings ended up being 7/8"-18 machine thread.

Like Injuneer said, M22 oil drain plug will work perfectly. You can get them at any auto parts store for a newer model dodge diesel for a couple of bucks a piece.

Well, after doing some more research, I found the answer to my problem. I ended up having to get the AIR tubes off of a 1994 LT1 to fit the headers. Evidently GM changed the fittings in mid '95 to a newer design more like the '96-'97 LT1's :rolleyes:.

http://i323.photobucket.com/albums/nn475/slimjim_350/IMG_5825.jpg
This one fits much better.

Thanks for all the help.

I'll post pictures of the install when I get everything going.