Stay away like Jody said.
I have a 13" kit from Precision on a 69 Camaro, and a 14" from Prodigy on a 69 Camaro both are Wilwood kits. The Precision brackets, hats, custom stuff doesn't fit at all we had to modify it heavily. The kit from Prodigy was a Wilwood bolt on kit and fit like a dream!
And give Frank a call he is the brake_man.