Obtaining quite good intel on the F-14 Tomcat – from the USA – proved quite easy for the KGB.
No, no Iranian F-14 was ever ‘given’ to the Soviets. No, the Soviets never made parts for TF-30 engines of Iranian F-14s, nor have they developed the Zaslon radar or the R-33 missile for their MiG-31 on basis of any kind of intelligence – from Iran. The Soviets were never left even anywhere close to any of Iranian F-14s.
It doesn’t matter who in the West has released any of such rumours, all are wrong. Similarly, all the photos purportedly ‘showing ex-Iranian F-14s undergoing testing (“against MiG-25s”) in the USSR’ – are fake.

(Actually, if at all, then it was the details of the MiG-31, Zaslon and the R-33 that were revealed to the CIA – and then by Adolf Tolkachev, one of chief designers at what is nowadays Vympel institute, and that already in 1979, i.e. before the MiG-31 entered operational service in the USSR.)
The Soviets did not need to ‘steal’ or ‘get’ any Tomcats: obtaining quite good intel on the F-14 – from the USA – proved quite easy for the KGB. Perhaps ironically, the rest came from diverse of books. Gauging by specific illustrations in Soviet internal publications, they did make extensive use of Mike Spick’s ‘Modern Combat Aircraft: F-14’ (Salamander, London, 1983).
Already in the same year, the Soviet air force published a related booklet ‘Naval Fighter F-14 (US Navy)’ – see the attached scan. BTW, this was ‘nothing special’.

They’ve had such ‘tactical manuals’ for all other major types of Western aircraft, too – including F-4s, F-15s, F-16s, F-111s, E-2C, E-3A, even for the F-117A and the B-2A: arguably, only top-ranking fighter pilots were getting these to see (reason for this was the – ‘complex’ – training system for all their pilots), which is why they remain relatively unknown outside specific circles.
The US Navy retired the iconic Tomcat on Sep. 22, 2006 and today the F-14 remains in in service with the Islamic Republic of Iran Air Force (IRIAF).
In January 2007, US Department of Defense (DoD) announced that sales of spare F-14 parts would be suspended over concerns of the parts ending up in Iran and in Jul. 2007 the remaining US F-14s were shredded to ensure that any parts could not be acquired.

However in Oct. 2010 IRIAF commander stated that his country was overhauling its F-14s and mentioned that Iran-made radar system had been installed on the fighter.
Moreover in the summer of 2010, Iran requested that the US deliver the 80th F-14 it had purchased in 1974, but delivery was denied after the Islamic Revolution.
More interesting F-14 stories written by The Aviation Geek Club contributor Tom Cooper are featured in Helion & Company In the Claws of the Tomcat.
