GRU layover customs process
 

I will be landing in Terminal 3 at GRU on an international flight and will have a 6.5hr layover before a domestic departure from terminal 4.
What are the chances I can remain in Terminal 3 for a while(spend time in a lounge) and then go through customs and take the bus to Terminal 4?

arriving on UA, departing on Azul.

Zero chance, You will get your bags and immediately go through customs (after immigration of course) and get dumped out post security.

First flight is international, second is domestic?

#1 has it right. Only place you can go before customs is the large Dufry duty free shop. You'll go through immigration, wait for your bags, then go through customs. Then you take your bags to a transit desk, check in there, get your second flight's boarding pass, and then you go through domestic flight security and proceed to your gate (bus to T4 is after security, I believe). Airline clubs are inside security, on the international side; you can't get to them.

I recently landed at T2 on an international flight and departed from T1 on a domestic flight. Only club outside security I could use was the overcrowded American Express Centurion Club. I've run into this more than once. If you find a way around this, let us know.

Even if you can't stay in a lounge, I suggest you stay at T3 as much as possible, even landside. There is NOTHING in T4, except a snacks counter.

I can't believe they cannot move Azul to T1/2 after the international flights have been removed from there. T4 is just a glorified warehouse with a new paint and some chairs.

Yes -- the bus from T1/T2 to Terminal 4 can be found outside the arrivals area of Terminal 4. It is indeed after security.

Hotel Check-In at 700am GRU?
 

Oops - wrong post!