Neither are Ford recommended service replacement hoses for Mustangs. In the 1975 edition of Ford Car Parts (aka the MPC), C5AZ-2078-A in a 12 1/4 inch long hose for full size Fords (both sides), 1965 all fronts, 1966 drum fronts only. C5DZ-2078-A is listed as 13 15/32 inch long, a service replacement for 1965 Falcons (both sides). Both hoses are listed in the 60-68 MPC for the same applications. Mustang drum replacement hoses (both sides) are 13 1/4 inch long and should be service number C5ZZ-2078-B, and for dick brakes, C5ZZ-2078-A, 15 inches long.
For Mustangs before 8/17/64 (a 64 1/2 Mustang), the service number is B7AZ-2078-A, 15 inches long.
Jim