76 Dart Sport front disc brakes

I assume you mean you're running the factory 10.95 brakes (brakes are measured by rotor diameter, not wheel diameter), which usually came from the factory with 14" wheels. The easiest upgrade that clears your 15" wheels would be to go to the factory 11.75" discs, which would only require you to replace the rotors and caliper brackets- all else remains the same. Dr. Diff has all the parts you need if you can't source them locally.
Brakes :: Front (doctordiff.com)
It's only a couple hour job, and that includes a beer or two along the way.