In 1970, the first project to modernize the Su-17 aircraft was launched. The installation of the new AL-21F engine led to a reduction in the midsection of the fuselage, and changes occurred in the avionics and arsenal of weapons. An interesting fact is that during the creation of the AL-21F engine in 1965-1966, the study of the American J79 engine from the captured F-4 Phantom fighter from Vietnam had a significant influence.
Su-17M and Su-17M2 built (excluding for export analogs of Su-20 and Su-22):
. Su-17M (1972-1976): 253
. Su-17M2 (1974-1977): 268