I noticed some A-Body cars have them and other don't. The rubber flap that is attached by staples on the inner fender wells near the A-Arm suspension. I supposed it is to help stop water from infiltrating inside the engine compartment when driving in rain.

Are these flaps necessary and what function do they serve?

If they fall off, are they simply stapled back on?

 

Ease of access to upper control arm studs, shims, etc. & ease of access to any points contained within, above and below the UCA assembly and various sorts of nefarious activities on other engine parts (especially on the passenger side). I don't believe they were OEM equipped. I believe they are an aftermarket add-on. I have them on my '71 A Body and they make a wonderful access point. They can be purchased via many automotive parts supply houses.

 

 

The rubber flaps keep water and dirt from infiltrating the engine compartment.

The staples that the factory used are the toughest and hardest staples to bend,

I found it easier to pull the inner wheel liners to install them.

 

They are factory equipment.

 

I realized that when I viewed the post by matt68F-85. I love the flaps.

 

 

If you drive in the rain without the flaps, you will eventually crack the exhaust manifold.