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WATKINS GLEN, N.Y. (AP) — Jimmie Johnson has seven career starts in the Daytona Prototype division of the Grand-Am Rolex Series, all at Daytona International Speedway. That's about to change.

Always eager for seat time on a road course, Johnson is splitting time this weekend between the Sahlen's Six Hours of The Glen at Watkins Glen International on Saturday and the Sprint Cup race on Sunday at Pocono Raceway in Pennsylvania.

"It's going to be a bit of a challenge time-wise, but I'm very excited to have this opportunity, so hopefully it all works out," said Johnson, who will co-drive the No. 99 with Alex Gurney and Jon Fogarty for Gainsco/Bob Stallings Racing. "The big thing is the timing of it. There's a good chance I'll only have 10 minutes of practice in that thing before I get in it and have to race it."

Johnson also co-drove for Stallings at the season-opening Rolex 24 at Daytona in each of the past three years. He finished second there with Gurney, Fogarty and Jimmy Vasser in 2008.

"I'm very excited that we were able to make this happen," Johnson said. "I think most people know how much I want to win on a road course and also in a Grand-Am car. It would be pretty cool if we could pull it off."

Despite capturing a record four straight Sprint Cup championships, Johnson has yet to win a Cup race on a road course in 16 tries. It's a gap in his resume that he'd dearly like to fill, and it's a big reason he did double duty at Watkins Glen two years ago, also competing in the Nationwide race.

"I think that it bothers him," said Jeff Gordon, Johnson's teammate at Hendrick Motorsports and winner of a NASCAR-record nine road races. "I think he's really worked hard at it over the years and it's that one (thing) that's eluded him. I think he feels like he can probably win just about anywhere. There's a couple of tracks maybe that they're not as good at, but it's just like Bristol was a track on their list and they went there and won that race (in March)."

Johnson has raced 11 times at Watkins Glen International — eight in Cup and three in Nationwide — but never traversed the famed "boot" section of the 3.4-mile circuit used by the IndyCar Series. The shorter 2.45-mile NASCAR layout does not include it.

That was part of the appeal of making the commitment to the Grand-Am race.

"I've always wanted to run the boot," said Johnson, who won the pole for last August's Cup race at Watkins Glen but finished 12th. "I need to get in the car and make some laps. Hopefully, there won't be any weather issues."

The weekend promises to be hectic. Johnson arrived at Watkins Glen early Friday morning and turned five laps in about 15 minutes before rushing back to Pocono for afternoon Cup practice.

"I talked to Jimmie briefly about it when he told me he was doing it," Gordon said. "I was a little surprised that he was going to do that on a Saturday. It's pretty ambitious, no practice or anything, just to come and jump in the car. I think it's just his desire to want to run a car that drives like that at Watkins Glen."

Johnson is entering a long-standing rivalry between Bob Stallings Racing and Chip Ganassi Racing with Felix Sabates that's simmering again. On Monday at Lime Rock Park in Connecticut, Fogarty slammed the No. 1 BMW Riley of Ganassi teammates Scott Pruett and Memo Rojas on the first turn of the race. The Ganassi car, piloted by Rojas, was heavily damaged and eventually forced out of the race, and the series points leaders finished last.

The teams also clashed twice in the 2007 season finale at Miller Motorsports Park in Utah. Fogarty slammed into Pruett while making a pass and Pruett returned the favor later in the race with Gurney driving the No. 99. But the Stallings team finished ahead and won its first Rolex championship.