Smog tube inserts
 

I am using a non functional smog pump what had anyone done to close off the exhaust to the manifold tubes

I have one smog system that is non functional. I took out the inserts and put in a button head socket cap screw. One similar to this, but without markings on the head. Smog pipes seal nicely against these.

Roofing nails work great

I used steel rod and welded a lip on it like the tubes had. Just slips in the hole where the tube was and the upper tube clamps it in place.

1/4" clevis pins fit perfectly in the tubes & it has a flange that will seat against the manifold. Pull those long tubes out of the manifold or the nut on the tube won't look correct. No welding is needed. I did this on my big block car at 83k. At 157k they looked just fine. Use a BB in the vacuum hose from the carb. to the deverter valve. I just mentioned all to Larry Christenson & that's what he said he would be doing. Really easy....Joe

I used the same as X66714....clevis pins work great!

I followed this for mine…was pretty simple and straight foreward. http://www.broachbuster.com/id64.htm

thanks I am going to try the clevis pin trick thanks guys

I bought these @ my local HDWE store... https://www.amazon.com/Clevis-Imperi...07D3YQ3DV?th=1

What is the reason you want to take the tubes out ?

The objective is the leave the tube in but make the system in-op. The clevis pins keep the exhaust out of the tubes...Joe

I tend to remove the stainless injection tube, put them in a bag saved for future use as needed, & install a suitable mechanical "plug" (i.e. Nail, Screw, Clevis, Machined plug) UNDER the Nut of the Smog distribution Pipe manifold or "Tree". I see no reason to leave the injection tube flapping in the breeze of the exhaust gases path.
I do not like the PaceCar jeff method since it potentially damages the manifolds (Tube) female tapered seat.

Good topic with Lots of great ideas and a variety of methods.