Reagan vs. Kennedy...
Without an incumbent Democrat to blame, Reagan's conservatism will likely seem too radical for the general populace. However, Ted has major issues, and though probably not too liberal to be elected in a good Democratic year, Chappaquiddick pretty much ended his non-Senate career. He likely wouldn't run, instead letting Mondale win the nomination.
Reagan wins in a squeaker (against Ted), gets squashed in '84.
If Ford wins in 1976, Dole will probably get the nomination in 1980.
Wouldn't Ford run again? I don't believe the 22nd Amendment would block him.
And Teddy getty nominated is near-ASB, never mind him being elected. 1980 is a promising year for Democratic Presidential contenders ITTL. Teddy gets crowded out, if nothing else.
Though, one of the ways that you could get Ford reelected is Nixon holds out longer, and Ford never pardons him. In the process, Ford avoids the 10-year limit...
Kennedy may not have run; he was always ambivalent about running for president and ran in 1980 partly because he felt nobody else was willing to challenge Carter. Without Carter in the WH, Ted might have held off as he did in most other years when the nomination was free OTL (1976, 1984, 1988).
You may have had a very different cast of Democrats emerge. People like Gov. Hugh Carey of New York, Sen. Adlai Stevenson III of Illinois, Gov. Reubin Askew of Florida - all of whom major Democratic pols of the late 1970s who didn't run in 1976 or for whom the political calender just didn't work out.
It would have been interesting to see a Ford administration in 1976-80. Would he be the Republican equivalent of Jimmy Carter? Would he equally mishandle the Iran hostage crisis as well?
John Glenn could be a real possibility as he polled second to Mondale in '84, I think that would be really fascinating. And Gary Hart would be a good VP for any number of candidates if he didn't take the nomination himself.