You speak as though Iraq had none of the similar problems that Iran did at the time:
en.wikipedia.org
en.wikipedia.org
en.wikipedia.org
Iraqis faced 2 major uprisings throughout the duration of the Iran-Iraq war. From Shia's in the south and Kurd in the North. Both were backed by Iran and Israel. Covert Support to Iran itself was provided by Israel + The USA
en.wikipedia.org
Remember if you read my initial post the Iraqis did not maintain a heavy advantage in 1980. Iran in fact had a much more technologically superior force - especially when it came to Air Power. The Iranian Air force did not Halt after the revolution as they had spare parts to maintain fleets lasting until 1982 at very least. The F-4 phantoms and F-14 flew throughout the duration of the conflict. Yes in lesser numbers but both were potent planes at the time. The Iraqis only really gained technological superiority around 1986 but they still faced the problem of being heavily outnumbered, facing a foe backed by US + Israel and Syria giving Iran intelligence and providing overflights for their air force.
Iraq was attacked from both sides, faced a Hostile internal SHIA and Kurdish population which outnumbered the loyal Sunnis and had a massive population disadvantage. Given the circumstances they performed quiet well as Iran should have been able to at least capture Basra given their manpower advantage and put Baghdad under legitimate Risk of falling. None of which happened.