I need something to plug the holes on the unit out of which the two pipes come out. (passenger side, near the firewall)
Does anyone know the thread size for a bolt that would fit in there?

 

Anyone?
I took the pipe to a couple of hardware stores today and they couldn't find something to match that thread size. I would leave it the way it is, but I might decide to put the A/C back on later on...

 

Well, its probably metric so maybe you could get a feeler gauges and see what types of threads it has on it. I'm not sure if they are two different sizes or not but something tells me they are. Once you measure the threads, go a tracktor supply store or your local race shop. Napa but then you have to be more specific cause they have to order from somewhere else.

 

I don't know if this will help but on the bottom of page 2 of my car domain site (link in sig) it shows what I did to plug it. We used a rubber cap and a pipe spacer to plug the hole. Just some stuff I had laying around the garage.

 

Madwolf,
The top hole takes an M22 x 1.5 (same size as the plugs for the exhaust manifold when removing the AIR pump) and the bottom hole takes an M20 x 1.5. If I remember correctly, I got them at Autozone. The top plug could be a M22 x 1.0 if you can find one. Mine sticks out just a bit; nothing major. The pic below may give some idea how it will look although the firewall unit is hard to see. Bottom plug is visible just below the bay brace. Hope this helps!

http://www.extreme-z.com/appearance/...small_DSC_6760

 

Thank you!
I still have those plugs in my stock manifolds so I will take one out and use it on top and buy the other one for the bottom.

 

Just so ya know, the air pump thread is NOT metric. That may work satisfactory, on the exhaust, but be careful on AC.

 

I tried several different sizes and these fit the best on the a/c unit. Regarding deleting the air pump, the metric plug is the only size I have ever seen recommended on this board for the exhaust manifolds. Just fyi.

 

That is correct. Everyone is using the metric M22 x 1.5 bolt for their 93-95 cars to block off the AIR fittings on the exhaust manifolds. I took one out of my old exhaust manifolds and it fit right in the A/C hole (no thread interference whatsoever). The M20 x 1.5 was harder to find (no local parts store carried it) but my brother picked one up for me from a Chicago store.
Thanks again fastcamz28!

 

The proper method of determining thread size and pitch is with a thread gage and a micrometer.
Just FYI, I've attempted on more than one occasion, to qualify the correct thread size and pitch. Obviously, the posts were not read, or were forgotten. I've posted the correct thread, and also noted the metric plug WILL fit, as the plug fits with enuf slop to allow minor cross threading. Most will find this acceptable. The fact is, you won't find the correct thread plug. Do not believe one exists. Rather than fabricate a plug of the correct thread, the easier route to take, is use a readily available metric plug. Those that use the metric plug are free to use that which they choose. I merely noted it is NOT correct to label it metric, because it is NOT a metric thread. To state so, is WRONG!
"Everyone" and "nobody" are among the most abused words in the english language. To state "everyone", would include me. Do not include me in that group. I chose to modify a (correct size) tubing fitting into a plug. I have this 'thing' about using the correct part for the job. The cross threading is minor, and a metric plug, though not made for the application, obviously has been used to the satisfaction of many, but not all.

 

You OK man?

You do realize we're talking about plugging a hole in a cast iron exhaust manifold right? Yes, I took a metrology class and have enough shop experience to determine thread and pitch size, but again, you do realize what we're talking about, right?
Ohhh.. nevermind. I know where this is going already.

 

That is why I stated the following:
After these comments:
and....
I gotta wonder.
Oh, I'm fine. That question leads me to believe, you may not understand my intent here. After going to great effort, to make my intent clear.... well.... sometimes I do not succeed.
Fact is, I'm fine with whatever people choose to use. It's their vehicle. But when someone leads others to believe it's a metric fitting.... Well, with that, I take issue.

 

Arnie, I don't think anyone is saying it is a metric fitting (at least that was not my intent); just that the only commercially available plug that seems to fit is a metric plug, for whatever reason. Nobody is doubting you about it NOT being a metric fitting! Your intent is clear and I appreciate your efforts to clarify. I think we all agree that, although these fittings are not metric, a metric plug does meet our objective.
Thanks!