Reagan would probable win the nomination, however it could be a tough fight. Bob Dole could benefit from any rally round the flag events, similar to Carter in OTL. That being said Reagan is still likely to beat Dole and whoever runs to represent the Liberal Republican wing. In the general Reagan could be in an awkward position if the economy is still in difficulties. Reagan benefited against Carter because he was the opponent, many of the voters in 1980 chose Reagan despite his platform (which he did moderate while running in the general). As the nominee Reagan would be running for a fourth GOP Term, while being accused of benefiting the wealthy and going against the New Deal consensus. These attacks which partially helped keep Carter in the race would do even better from a non incumbent running against 12 years of GOP economic failure.
Onto Ford. If Ford wins he would probable still be seen as he is today, as a well meaning but inept individual, his failure to Whip Inflation Now (WIN) would still be a defining element of the public memory. He would have been president during two recessions, the 1974-1975 recession and the 1979-1980 recession. In Foreign Relations many of the Neo Con's such as Cheney and Rumsfeld first against power in his administration, and would gain more power in a second term with Kissinger out. His foreign policy would be seen as more hawkish as opposed to the real-politic of Dr Kissinger. Unlike Reagan, he won't receive the (underserved) praise of ending the Cold War. Historians would argue that he did, but the public perception would not share that image. Socially he would be less liberal than Carter but not as right wing as whatever Republican Administration came in the late 1980s or the 1990s (1988 at the earliest though probable 1992 or 1996). He would be ideologically orphaned.
A interesting though perhaps stretched comparison would be Malcom Fraser in the 1970s, albeit less socially liberal than the Fraser Government. He would be known for 1: coming to power as the result of a serious constitutional crises 2: presiding over years of economic difficulty and misery without much success 3: not being conservative enough for the right and too right wing for the left, 4: possible being the last president before the neo liberal revolution of the 1980s, 5:a hawkish anti communist foreign policy.