Indeed, VARIG was serving Belem with the B767-200ER at this time in 1993 and their service included an interesting domestic milk run. Here's the sched.....

RG 300: Rio de Janeiro (GIG) 14:45 - 16:45 Salvador (SSA) 17:20 - 18:35 Recife (REC) 19:15 - 20:30 Fortaleza (FOR) 21:05 - 22:20 Sao Luiz Ma (SLZ) 22:50 - 23:55 Belem (BEL) 00:30 - 01:30 Manaus (MAO)
Freq: Daily
Equip: 767
Service classes: F/Y - 18 seats in F (2-2-2 config) & 176 seats in Y (2-3-2 config)

And until I looked up the schedule today, I had no idea that Sao Luiz Ma was a city in Brazil, let alone that it had 767 service.

VARIG was also operating a flight from Belem to the U.S. at this time. Here's that sched....

RG 802: Fortalez (FOR) 09:15 - 11:00 Belem (BEL) 12:00 - 16:00 Miami (MIA)
Freq: Mondays only
Equip: 767
Service classes: F/Y (same seating config as above)