Austin Dillon using the number.
The move has been long anticipated because car owner Richard Childress has allowed his grandson to use the No. 3 as he's moved through NASCAR's ranks.
"I know in my heart, today, as I sit here, Dale Earnhardt is smiling down," Childress said at Wednesday's unveiling. "He would want to see this 3. He didn't want it to ever go away. But I felt it was the thing to do right after Daytona, and I know today that he's accepting this highly. I knew him that well."
The number has not been used since Earnhardt's death in the 2001 season-opening Daytona 500. The car was rebranded to No. 29 for Kevin Harvick following Earnhardt's fatal accident.
But Dillon has been using it NASCAR national competition since 2009, when he made his Truck Series debut in the No. 3. He won the Truck championship in 2011 driving the No. 3 for Richard Childress Racing, and the Nationwide title this year in the same number.
Childress kept the number out of the Cup Series, though, intent on hanging on to it for the right driver.
"We held the number, I've been paying NASCAR for it throughout the years and Bill (France) Jr. told me 'You know, if we're ever challenged, we'll have to let someone have that 3,' " Childress said. "But we weren't, and I knew that the right opportunity would come. It would have to be an Earnhardt or one of the Childress family that we would put behind that."
Childress said he publicly floated the idea of allowing Dillon to use the No. 3 at the start of the year to get a fan response, and got 90 percent positive feedback the day after he mentioned the number.
"That said to me it was time, and if Austin wanted to it was his choice," Childress said.
Dillon said he was ready, and it's the only number he's ever used in NASCAR.
"My grandfather has done a great job of teaching me how to handle certain responses to things, and I think we're going to go forward with it," Dillon said. "I've heard a lot of good feedback from the fans, and every time I'm at an autograph session I've had someone ask what's going to happen. They are excited and we are, too, at RCR.
"It's what our sport was built on -- family and history -- and a great opportunity for all of our sport to see this No. 3 back on the track."
The No. 3 Chevrolet will be sponsored by Dow, Bass Pro, Realtree and General Mills. Neither of the two paint schemes unveiled Wednesday resembled the dominant black cars driven by Earnhardt, winner of seven Cup titles and a first ballot Hall of Famer.
But Childress believed just having the No. 3 back in the series will help resurrect Earnhardt's legacy.
"My hope is that Dale Earnhardt fans will be re-energized and say 'Hey, it gives me something to look at,' " he said. "We know we aren't going to please everyone. We know that. We are going to do our best to make them proud and I know Austin will. I think the new fans will learn a lot about the great Dale Earnhardt by watching this."
Gil Martin, who led Harvick to six berths in the Chase for the Sprint Cup championship, will be crew chief for Dillon.
Childress said he's consulted with Dale Earnhardt Jr. and his sister, Kelley, every time he's moved the No. 3 to a different level on the track and the Earnhardt family has been supportive. Earnhardt Jr. declined to use the No. 3 following his father's death, but has raced the number in the Nationwide Series.
"I would be worried if I didn't think he'd respect it or not understand the legacy, but he does. I know he does. He appreciates it," Earnhardt Jr. said last week of Dillon using the No. 3.
RCR will field a three-car Cup lineup next season with Dillon, Paul Menard and Ryan Newman.
Ty Dillon will run a full Nationwide Series schedule, and Childress said Wednesday he's sold his Truck Series assets to Gallagher Motorsports.