The weigh in for Saturday's World Boxing Organization title fight took place outdoors at the north end of the huge facility on a makeshift stage surrounded by hundreds of fans who were kept behind barriers.
"I am not going to promise you a knockout, but I will do my best," Pacquiao told the crowd. "We have a strategy that we created in our training so people are going to be surprised."
The 31-year-old champion Pacquiao, who has won 11 consecutive fights since losing to Erik Morales in March 2005, weighed in wearing grey and blue boxer shorts and white socks as he tipped the scales at 145 pounds.
Ghana's Clottey, whose only career losses have been to three world champions, weighed in at 147 pounds.
Both fighters appeared relaxed at the weigh-in and when Clottey tried to engage Pacquiao in a staredown, the Filipino boxer just looked down and laughed and then joked with members of Clottey's camp.
Pacquiao, who will be fighting in front of the largest crowd of his career, told the throng outside Cowboys Stadium that he is hopeful of a knockout.
Pacquiao also talked about his plans after the fight in which, win or lose, he will host a bash and sing with a band.
"After the fight we will have a party," Pacquiao said.
Clottey's trainer Lenny DeJesus said his fighter should reach about 160 pounds by the time he steps in the ring, giving him a possible 10-pound weight advantage over Pacquiao, who won his first title at the 112-pound flyweight class.
"I will be the stronger than any fight before," underdog Clottey said. "I am ready."
Promoters are expecting a crowd of about 45,000 for the first fight card in the new stadium, which opened last year. The stadium is the home of American football's Dallas Cowboys and has been modified to suit a boxing ring which is dwarfed by the size of the venue.
Fighters' images will be shown on a 72-foot tall, 40 million-dollar high-definition jumbo telescreen, making it possible for those in the nosebleed seats to see what is going on in the ring.
Pacquiao (50-3-2, 28 KOs) has looked unstoppable in his last three fights and he isn't showing any signs of losing power as he fights bigger and stronger opponents.
His plan is to wear down the 32-year-old Clottey on Saturday so he can finish him off in the later rounds.
"He is the greatest fighter of his era," said Pacquiao's trainer, Freddie Roach. "He has seven world championships. When people say who is the next Manny Pacquiao from the Philippines that is a lot of pressure to put on somebody.
"You might have a couple more champions from the Philippines but you are not going to get another guy that's going to win seven world titles in our lifetime. He is a 'once in a lifetime' deal."
Clottey's only losses have been to world champions -- Miguel Cotto in June 2009 by a close decision, disgraced boxer Antonio Margarito in 2006 and Carlos Baldomir by a controversial disqualification in 1999.
Margarito, who was caught using illegal hand wraps under his gloves for a fight against Cotto, also attended the weigh-in, as did actor Robert Duvall, who joined the two on the main stage.
The fight will start about 10:15 pm Dallas time (0415 GMT) and organizers expect it to be shown live to 80 million homes worldwide.
Source: AFP American Edition