Any tips on introducing amazons to eachother?

[Halo]

Hello everyone!

We have a Mexican Red Head Amazon, Alfie, who has been with us and gets along with the other birds in the room with him (male CAG and male Goffin) and we are getting another Mexican Red Head Amazon on Wednesday, Pedro, and we are hoping to be able to keep them in the same cage since Pedro's cage is 5'x3'x7'.

Anyone have any tips on getting them to know eachother safely? Pedro has been around other birds as well (macaw and quaker) although I'm not sure if they are ever out of cage together or if they interact at all (although I really hope so since all my fids get together at this point and I'd hate for that to change). Both are male and both are approx. 15 years old.

Thanks!