MG Car Repair: Preheat connection, professional mechanics, frame members

Question
QUESTION: I have a simple question but can't find the simple answer on my own. Doing a engine/tranny removal on a 1979 Midget. Have project almost ready for the removal step but lack the ability to remove the Cat convertor so the engine can clear the frame members. The workshop manual says that the "Pre-Heat " elbow ,for the air system ,which is below the intake manifold and blocks one row of bolts for removal of the convertor ,has two tabs to depress and the elbow should come out.  I have looked , wiggled and felt all around the elbow and can find no such animal. I do not want to just pry the elbow off and damage it as it appears there is no replacement for this part. surely I am missing something. Any ideas?  Thanks

ANSWER: Hi Mark, The only tabs that I know of are on the preheat duct pipe which is just forward of the lower part of the exhaust manifold. If you can't get the CAT off, just remove the intake and exhaust manifolds. Then tie the whole assembly over to one side and pull it that way.
Howard

---------- FOLLOW-UP ----------

QUESTION: Thanks. I was trying to prevent having to do that exact thing and that's the only way I see to do it as well. Worry about old bolts etc and making more challenges for myself in the process.  But one must do what one must do. One last question (? ). Curious to what the actual (approx) time would be required to pull the engine / tranny and replace the clutch and , of course, reinstall everything back to square one? Few professionals really want to work on these cars as too old, unfamiliar and no quick parts available.  It would make me feel better if I knew I had saved a sum of money doing it myself !! Plus I'll really know what was done.

Answer
Hi Mark,
The job for professional mechanics takes 7.1 hr at what ever their shop rates are. Many times on different cars the manifolds are removed and tied off to the side because pipe to manifold nuts can be rusted also and then require the removal of the manifolds anyway. Many times it is a judgment call as to weather the manifold to pipe (or CAT) are rusted more than manifold to head. And I have found many that both are rusted solid and need special attention to fix. Many just break off and need to be fixed by drilling out and taping the threads again. This time is passed on the the customer as it is not the mechanics fault they are rusted solid. I usually got 90% of the stuck nuts off of manifolds because I could usually get a torch in and heat the nut red and it would usually come off then. Many of the original nuts on the manifolds were a different steel alloy and could be removed. When a mechanic would replace them with a standard steel nut, they could easily rust solid.
Welcome to mechanic's world, not always easy.
Howard