Hi John A,
The correct spelling of the town is Pico da Pedra and the full name of the church is Nossa Senhora dos Prazeres. All of this is on the island of Sao Miguel. I mention this only because, when you do an Internet search, "San Miguel island" is off the coast of California. "Sao Miguel island" is one of the Azores. "Pio da Pedra" pulls up nothing. If someone later searches these archives for Sousa, Dias, or Pimentel from Pico da Pedra, your post will not come up. The computer can't search for alternative spellings. Also, one of the sites I mention below will turn up nothing if you make a typo.
If you are in your 20s, "grandpa" may be a man in his 70s or 80s. Those records are not online. They are at the Civil Registry in Ribeira Grande. You would need to hire someone over there to retrieve the record for you. If you are in your 70s of 80s yourself, then your grandparents were born probably in the very late 1800s and those records are online (published by the Azorean government at the Centro de Conhecimento dos Azores (we just say CCA)). Use Tombo.pt to access them. You can either type in Pico da Pedra in the search box at the top left column or you can navigate the left column (Azores > Sao Miguel > Ribeira Grande > Pico da Pedra).
Happy hunting,
Cheri Mello
Listowner, Azores-Gen
Researching: São Miguel island: Vila Franca, Ponta Garca, Ribeira Quente, Ribeira das Tainhas, Achada