brake identity

[69ZZ]

Hi guys,this is my first post. I figured someone can help me with this. I have 2 sets of calipers that i would like to install on my 69 camaro,but i dont know from wich kind of car they are from.I have the brackets for the red ones and they seem to fit in the front,as for the black ones i dont have any brackets for them and i wish to install them in the rear (10 bolt diff).Can this be done?
Also what disc size i should use.
Is this setup worth it performance wise?

Thanks for any advice

[69ZZ]

this is the size of the piston area

[David Pozzi]

The black look like 70's corvette (C3) rear calipers.
The Red look shorter, I dont' think they are vette calipers. The Corvette rears are usually 1 3/8", fronts are 1 7/8".

C3 rotors are 1 1/4" thick, and 11 3/4" dia.