The only question left for the Indianapolis duo is what the final records will be when they quit playing.
"It kind of hits me knowing the fact it's still early in both our careers," Harrison said after the Colts beat Tennessee, 31-10.
"You just never know when it's going to end or what it's going to be when it's done. But the main focus is that we stay together and win football games and put that under our belts as well as a lot of wins, and hopefully some championships."
Young and Rice combined for 85 touchdown passes between 1987 and 1999 with San Francisco.
Manning is in his eighth season with the Colts and has six years left on his $98 million contract. Harrison is in his 10th and signed a seven-year deal last December. Last week, they passed Buffalo's Jim Kelly and Andre Reed for most yards passing.
"It's an honor and privilege to be able to call Marvin a teammate," Manning said. "He's an outstanding player. He and I have combined for a lot of touchdowns and a lot of wins, but it's because of a lot of hard work. He has a tremendous work ethic, and I feel privileged to call him teammate."
Indianapolis coach Tony Dungy isn't going to answer the question of whether Manning and Harrison are the greatest combination ever.
"I guess the numbers will speak for themselves. Those guys should get to play together for a lot more time. They may put up some numbers that will be hard to reach," Dungy said.
Chiefs -- Dante Hall tied an NFL record with his sixth career kickoff-return touchdown, a 96-yarder in the second quarter against Philadelphia. He now shares the record with Ollie Matson, Gale Sayers, Travis Wilson and Mel Gray.
Titans -- Running back Jarrett Payton, son of the late Walter Payton, was activated for his first NFL game yesterday when Tennessee promoted him from the practice squad. Helping to fill the void left by Travis Henry's four-game suspension, Payton carried four times for 37 yards in the Titans' loss to the Colts.
Eagles -- Defensive tackle Paul Grasmanis re-tore his Achilles' tendon.