David Haye and Dereck Chisora promised the knockout loser of their non-title fight on Saturday will donate $31,000 to charity.
At a joint news conference on Wednesday, where the bitter British rivals were separated by a metal fence, one of the only two things they agreed on was helping out charities if one or the other is knocked out at Upton Park.
Chisora picked a children's hospital, and Haye chose a bone marrow charity for minorities.
They also agreed to blood testing for doping, if asked.
Otherwise, the hype flowed freely between the boxers, who have attracted 29,000 spectators for a fight that hasn't sold out.
"I can't think of such a fast-selling fight involving so much publicity since we bought Mike Tyson back, over 10 years ago," said Frank Warren, Chisora's manager.
Haye and Chisora came to blows in an infamous press conference confrontation in Munich after Chisora's defeat on points to Vitali Klitschko in February.
The brawl tarnished the reputation of both men, leading to the Luxembourg Boxing Federation sanctioning their fight, and not the British Boxing Board of Control. Neither boxer was apologetic for the ugly scenes that were broadcast globally from Munich.
"I regret saying I would shoot David," Chisora said. "But do I regret getting hit on the sucker punch? No."
Haye said: "I don't regret anything. I was defending myself like anyone else would."
The 31-year-old Haye, who hasn't fought in a year, refused to speak about his future after Saturday's fight but Warren spoke of a potential matchup for Chisora with Wladimir Klitschko.
"If Dereck comes through on Saturday like I know he can, then the biggest fight here in the UK would be Wladimir Klitschko," Warren said. "Get this one out of the way and that is the direction we are going in."