Pepper, who plays the late racing legend Dale Earnhardt (search) in the ESPN movie "3," said meeting Junior and getting his approval to do the TV movie was "like getting the monkey off my back."
"It was a great experience for me just to sit down and talk with him and just hear some old war stories about his dad," Pepper told reporters. "And hear how excited he was about our film."
Pepper went to racing school to learn how to drive the 3,400-pound stock cars before shooting the movie.
"They were the real deal," Pepper said. "Eight-hundred horsepower NASCAR machines. And you're strapped in and the first day you're doing 110 mph just as an introduction."
The experience left Pepper, who also played New York Yankees great Roger Maris in the ESPN movie "61," gassed.
"By the second day, you know you're reaching speeds up to 170 mph," he said. "And the G-forces around these 32-degree banks are pretty intense.
"It was one of the most exhilarating experiences of my life."
"3" airs Saturday night on ESPN.