Ali/Frazier would have occurred in 1969 or 70 at the very latest.

He also would have been able to fatten his title defense total against the likes of Jimmy Ellis, Bonavena, and Buster Mathis.

I think Norton (w/Futch) would still give Ali a tough fight and Ali would underestimate him to a degree just as he did when they actually fought.

The irony is we would have ended up with a "Rumble in the Jungle" regardless. The big difference is Foreman would be challenging a 9-10 year title reigning Ali.