340 Intake Manifold Heat Shield

Many thanks to all of you for your advice. I will reinstall the heat shield with screws and Loctite.

One last question: Heater and bypass nipple are stuck is if they were welded to the intake. It is insane, even heating everything up with my torch does not change a thing. So i was thinking of welding a nut to each nipple and try loosen it with the impact wrench. Any better way to solve this problem?

Thanks a lot once more!