76 monza?

can i use a set of 7/76 monza front disc brakes and swap them to a 71 mustang?

Not without a heck of a lot of fabricating and machine work.
71 Mustangs had factory optional disc brakes, so all the correct stock parts are available and much easier than trying to cobble together Chevy parts on a Ford.

so where would i be able to get the parts to build the front end? i've already tried junk yards and they either don't have it or its too much. its about $400 for all the parts i would need of a 76 granada brand new from a parts store.