I am returning from EZE to ATL via GRU on 3/8. The EZE-GRU segment is on TAM, while the GRU-ATL flight is on DL. Unfortunately, I only have a one hour layover.

1st question: Can I check my bags all the way through, or will I have to reclaim them in GRU?

2nd question: Do I have to clear immigration in GRU or can I stay in a sterile zone?

I have connected in GRU but only to a domestic flight to GIG when I did have to clear immigration, etc.

3rd question: Is there any chance I get through all of this and actually make the flight?

Fortunately, I'm on the first DL flight back to ATL, so if I do misconnect, hopefully I can get on the later flight.