Broken off air tube fitting in exhaust manifold, now what?

[unrestored72Z]

So I found a set of factory exhaust manifolds, still with their smog hoses attached, all in poor condition.
I needed to heat up the injector fittings to get them to come out. Three were successful but for one, it just shaped off the head of the fitting.
What the heck can I do to extract the thread portion of the fitting, as well as the guts of the injector tube?
I could drill to get the scraps of the tube but what will allow the rusted fitting remains to spin out knowing it didn't even release when it had its head?
Anybody just drill these out and re-tap with standard bolt threads vs the very unusual pipe thread pitch the factory used?
Also, what do guys do with the pipe that goes into the head if not running smog, leave them intact or punch them out?
Do they even punch out?

Thanks

 

[FS87LT]

All of the replacement exh manifolds Chevy sold had all of the holes drilled in them, so they ALSO sold some square-socket plugs that went in those holes when not used. I found them in the Chevy parts catalog. With the square recess for a ratchet/extension, they looked much better than the pipe plugs most people used!

The "nozzle" has a flared end on it, just like a brake line, which the external nut holds in place. They should tap out, or similar.

Before the presence of an A.I.R. pump was needed for state inspections (in TX), many people removed the A.I.R. items somewhat early on, back then.

FS87LT

 

[unrestored72Z]

Thanks

So does that mean the tube taps out back up the manifold, or it gets tapped out thru?

Also, are the recessed plugs still available?

 

[bkmont]

Anybody just drill these out and re-tap with standard bolt threads vs the very unusual pipe thread pitch the factory used?
Also, what do guys do with the pipe that goes into the head if not running smog, leave them intact or punch them out?
Do they even punch out?

Thanks

If you wanted to clean up and keep the unusual factory threads, what size tap would be used to chase them?

 

[danbrennan]

When I still had factory exhaust manifolds on my Camaros, I used brass plugs, not steel, on my '74 Camaro. My '78 didn't have an A.I.R. pump.

Plug your GM A.I.R. manifolds

 

[unrestored72Z]

When I still had factory exhaust manifolds on my Camaros, I used brass plugs, not steel, on my '74 Camaro. My '78 didn't have an A.I.R. pump.

Plug your GM A.I.R. manifolds

Thanks Dan, good information although I wonder if I will be able to get my damaged connector out.

 

[unrestored72Z]

I wonder if manifolds like this which was not drilled for A.I.R. was aftermarket or factory?

 

[danbrennan]

I know the exh manifolds on my 1978 Z28 were not drilled for A.I.R. as they came from the factory.

 

[unrestored72Z]

Dan, what are the cast numbers for your manifolds, and do the later years match the earlier years to hook up to factory exhaust?
Maybe I will just try to find untapped manifolds.

 

[COPO]

Don’t drill the hole larger bc there’s a lip that stops the pipes from falling through.