OK so one 5.3 or any Fullsize v8 i guess, there two pieces of dark greyish foam that sits in between the intake and valley cover. one in front and one in back.
Do you have to put these back on? bc when i had the intake off, they fell off and idk how they went.

thanks

 

You only need those if you live in a very cold environment. They help keep your intake warmer. I removed mine as soon as I bought my truck.

 

I always thought they were to keep water & debries away from the knock sensors....

 

+1, they're there to keep moisture and junk out of the valley where the knock sensors are. There are coolant hoses going to the throttle body to keep it from icing in cold weather, and the intake doesn't need any extra warmth...

 

i wouldnt lose any sleep over it.