Jimmy McLarnin and Pop Foster. Pretty sure Foster left everything he had to McLarnin when he died, even though Jimmy had used his money wisely and was never short of a quid or two in retirement.
Actually, Jimmy had made some bad investments and was financially strapped when Foster died in 1956. Foster's inheritance money allowed him to live comfortably ever after.
Cus Damato and Mike Tyson. Ray Arcel and Roberto Duran (Arcel left when he thought Duran should retire) Dundee and Ali.
Joe Frazier and Yank Durham Yaqui Lopez and Jack Cruz Mustafa Hamsho and Paddy Flood Danny Lopez and Howie Steindler
Joe Frazier with Yank Durham and Eddie Futch, Durham passed away in 1973. Carlos Monzon and Amilcar Brusa, both remained together until Monzon's retirement in 1977.