The Ford Mustang 5.0 never used a 302 cubic inch engine. The 5.0L (302 cubic inch) engine was used in Mustangs, but the "5.0" designation refers to the engine's displacement in liters, not a separate engine family from the 302.
The last year Ford used a 302 cubic inch engine (in various displacements) in a Mustang was 1985. After that, the 5.0L engine was a refined and updated version, but still essentially a 302-based design.
