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Please see and comment on the attached image and video/audio.

Smoke machine was attached to tail pipe. Major exhaust leak points include:

1. intake/exhaust manifold assembly surface
2. exhaust deflection shaft openings
3. exhaust pipe o-ring

Is there a gasket or suitable gasket material for use at the intake/exhaust manifold assembly surface? There is no gasket there now.

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That would be good news if fixing your leaks gets rid of your unwanted noises!

I think it would be prudent to get the correct gaskets. They should be available from Max Merritt or one of the other suppliers.

I purchased a gasket set from Max Merritt. It contained the 3 block-to-manifold gaskets, the carb base gasket and the exhaust pipe gasket. There was no intake/exhaust manifold gasket.

Page 15 of the Service Manual Section XII Fuel and Exhaust says "In the event the exhaust or intake manifold is to be replaced, the manifolds may be separated at the milled joint of the manifold heat riser (hot spot). There is no gasket at this joint."

I did find this https:\\www.ebay.com/itm/383542313781.

If there was originally no gasket between the intake and exhaust manifolds, I would think that putting a gasket in will change the geometry of the mounting surfaces to the block. That may create more leaks at the block. One thing you could consider is using a sealer on that joint instead of a gasket. I've used VersaChem Exhaust Seal with good results in the past.

There is no need for a gasket there as it’s simply a heat chamber used to quickly open the automatic choke. It serves no other purpose that I can think of.

Please watch the video. That joint has the worst exhaust leak on the engine. Also, the joint is covered in soot.

Why is there smoke from the carb in the video?

I haven't had the manifolds off my car, so not speaking from experience here, but it would seem that something is misaligned.

This is the procedure from the service manual for installing the manifolds.




I would assume there is a bit of valve overlap, a brief period where the exhaust and intake valve are open at the same time which would cause smoke to come out the carb.

Question, you had the engine off when you were doing the smoke test, correct? With the engine running the air will be moving in the opposite direction from the smoke test.

I don't know what the internal of the heat box looks like between the intake and exhaust manifolds. But I do know the riser valve directs hot air up to the carb to get it warmed up faster. I would assume there is not a direct communication between the exhaust manifold and the air going into the intake. Does the intake side have it blocked off? I know there are holes going up from the exhaust manifold, but my assumption is the intake side of that is walled off. My manifold off my parts car is not separated out for me to check.

Maybe there's a crack on the intake side that is allowing air from the exhaust to get up into the intake/carb?