...no, not MiG-23, let alone MiG-29.
The task is to come out with an affordable (= no swing-wing, just one engine) performer, with issues of the MiG-21 adressed - short range and low-speed handling and maneuverability. Reasonable electronics, useful radar included, that can use better radar-guided missiles than the it was the R-3R. Uses technology of the day, so it could be produced in factories where the MiG-21 was produced.