The book below gives tremendous insight into the subject. Iran was able to acquire large quantities of spare parts needed for its F-14/AWG-9 fleet/radar and AIM-54 Phoenix rounds during the Iran-Contra scandal (during) the Reagan administration. According to the authors, the Iranians resolved all their spare parts issues by 1991 regardless. According to this book, the Iranians were offered the F-15 but chose the F-14 because it would defeat the F-15 in exercises nearly every time. The Tomcats agility, AWG-9 & Phoenix missile simply could not be ignored, (some say to this day). The F-14 only big Achilles heal seems to be its power plants, very touchy.
Iranian F-14 Tomcat Units In Combat- Cooper, Tom; Bishop, Farzad; Osprey Publishing, 2004.