1969 AIR emission exhaust manifold tubes

[hotrod34]

Does anyone know if you have to put the extension tubes in the exhaust manifolds before you put the tubes on? Its a non functional system, as per Bill Hodel, who happens to be on vacation til May 28. AIR tubes are plugged and air pump vanes removed. The tubes dont seem to tighten down 100% and might need that extra spacing to properly tighten. Do they need to be shortened? Any info will be appreciated.

[Dave69rag]

The air tubes will not tighten without the extensions in place.  The easiest fix is to use stainless pan head fastners in place of the extension tubes.  This will block off the exhaust gases from entering the smog tubes as well as make up the extra space needed to tighten them.

[x66 714]

I used clevis pins. They jam into the AIR tube & the head a good size for spacing & sealing. I also put a BB into the vacuum hose that runs to the diverter valve & removerd the vanes from the pump...Joe

[JohnZ]

#10 x 1/2" flat head stainless machine screws work perfectly as substitutes for the extension tubes; they seal off the hot gases from discoloring the finish on the air manifolds, and are the correct thickness to allow the tube nuts to tighten to the correct dimension, and can't be seen.

[Jerry@CHP]

We use RTV #101B with roofing nails in the smog tubes for the systems that we build.  No tube extensions. 

That works fine and will keep the plating from going away as the nails block much of the heat generated by the exhaust manifolds.

Jerry