Reagan picks former President Ford as his running mate in 1980. After the decisive victory over President Carter, Reagan’s term only lasts for two months: On March 30, 1981, he gets shot. Once again, Gerald Ford assumes the presidency. He runs again in 1984. Does he win that time?
Doesn't work, he'd be term limited anyway and unable in '84.
Now if we suppose Carter beats Reagan and Ford actually tried again, that would probably lead to Ford victory, narrow if Carter's second term pays off, the actual '84 if it doesn't.