Like OTL only bloodier, more dangerous, and with butterflies tied to these.
The grand American escalation in Iran -- the development from a cordial relationship and a few absolutely key bits of Cold War cooperation (particularly the TACKMAN monitoring sites along Iran's northern border used to monitor the testing grounds for all of the Soviet Union's under-development classes of nuclear missiles, mostly in what is now Kazakhstan) to a massive tidal wave of military aid worth many billions in 1970s dollars (so tens to hundreds of billions now), the escalation from a few thousand to nearly 50,000 American private-corporation employees, mostly defense contractors, oilmen, and technical developers (think Ross Perot's EDS computer office systems outfit, which also dabbled in defense contracting), plus a thousand or so rotating American military trainers/advisers attached to ARMISH-MAAG (the military assistance group for Iran) happened almost entirely between Nixon's reelection and the first months of Carter's term, so in your TL just after Ford's reelection. That will continue vigorously under a second Ford term and the US will be fully committed to the "Twin Pillars" approach to the Middle East (building up Iran and Saudi Arabia as the bulwarks against Moscow), not hesitantly like the Carter admin, and you'll see Ford's administration lobbying hard by the end of the decade for extra F-14s and AWACS for Tehran. But all of the social and economic pressures will still be there, even more so with Ford backing the Shah to the hilt. Now some of that will become more pragmatic when (and it is a when not if, he would either simply go because he was exhausted or because he was tired of losing bureaucratic fights to Rumsfeld and Cheney, probably once a Panama Canal treaty was settled) Kissinger retires and is replaced by someone, likely Poppy Bush but possibly someone else. Nevertheless the US will be all in on maintaining a Shah-based regime and when the Shah finally reaches a point where he has to admit to his illness the Ford administration will do whatever's necessary to develop and prepare what amounts to a military junta-as-trusteeship for the Shah's teenage son, possibly with a papering over with the Majlis led by somebody like Bakhtiar if not he himself. This may even sort of work if they're willing to shed enough blood to do it. But if the do that it's like shoving the lid down harder on a boiling pot, it only increases the pressure. And if you do something like bump off Khomeini there are people who will replace him, and they are younger and more politically agile (plus Twelver Shias love them some martyrs, much like evangelical Protestants do.) So after the Shah is terminal, things will bubble ever harder and when he goes things will blow. Hundreds, probably thousands, will die, there will be battles in the streets, some American firms will sensibly panic and start pulling their people out which will cause the Ford administration to junta harder in terms of aid and maybe even advisors. But all that just raises the specter of 1953, and this all comes down not only to the fact that the Shah's general staff were peevish and corrupt almost to a man, but that it relies on the regular Iranian enlisted man. The moment gunning down martyrs in the streets for a boy puppet of the god-damned Americans is too much for the average Iranian corporal, it all goes to hell. There were many forces and factors involved in the Iranian revolution (indeed for most of 1979 the reason we maintained and Embassy and relations was that there seemed to be a chance the Bazargan experiment would actually work, that observant but constitutionalist Muslims would run the country, the rival political gangs would finish settling their scores in the streets, the mullahs would go back to the mosques, and Iran would drift away from the US but still rely on occasional support to keep the Soviets at bay.) But those will now fragment and any settled government that is not hard-line enough to both voice the tidal wave of rage in the streets and organized enough to not get shanked by personal rivals will come in: real Robespierres of the velyat-i-faqih. At that point Americans in the country are hoist by how hard the Ford administration tried to keep this from happening. It will probably not be as neat, tidy, or self-contained as OTL's Embassy hostage crisis. And those attacks on Americans will lead to a major show of force to demonstrate 1) the Gulf will stay open to shipping, 2) the US will not put up with this, and 3) the Soviets shouldn't get too greedy. I wouldn't be surprised if a significant hostage crisis emerges from this, based on some particular gang of komitehs who want to show the Great Satan is a paper tiger because there are still some few thousands of Americans desperately trying to get home, including a more substantial presence around the Embassy/ARMISH-MAAG still there on behalf of the (now overthrown) junta to show America won't cut and run like in Saigon. When that happens Ford will do what Carter initially wanted to (and was talked out of it by Zbig Brzezinski who feared driving Tehran towards Moscow would screw up Zbig's grand plan to "give the Soviets their own Vietnam" in Afghanistan) and mine Iran's harbors. Where things go from there is anyone's guess.