Will Harvick-Busch tangle, can Junior break slump at Dover?

Throw in a rivalry between two of the sport's best drivers and Sunday's FedEx 400 Benefiting Autism Speaks is a NASCAR fan's dream.

While the Kyle Busch-Kevin Harvick feud is gaining most of the attention entering the race, it would be foolish for either driver to get involved in another altercation considering NASCAR has placed both on probation for the next four races. Another incident between the two could be more costly than the $25,000 each driver was fined for last week's episode at Darlington.

"It definitely affects how you race for the next four weeks," Harvick said. "We got the ultimatum yesterday of the explanation of how probation worked and how NASCAR expected us to race. I think the way that the next four weeks go was basically dictated to us yesterday in the NASCAR trailer."

So expect those two drivers to tolerate each other in the race while the other competitors have to find a way to conquer the Monster Mile.

On Friday, Dale Earnhardt Jr. was asked if these sort of rivalries and occasional dust-ups were good for the sport.

"It's not bad," Junior quipped.

But Earnhardt also pointed out that a racer has to race and not worry about whether the two rivals are battling it out on the track.

"You have so much to concentrate on with your own deal," Earnhardt said. "You hear about most the stuff going on through second hand. I just focus on what I'm trying to do; what my job is. Those kinds of storylines are for the fans. Let the fans enjoy it and let the fans think about it what they want. The rest of us are in here thinking about the race weekend; what we are trying to do during the race."

And what makes this weekend different from nearly every other track on the schedule is the concrete surface at Dover. The others are paved with asphalt, which is much more temperature sensitive but easier to apply a smooth surface. Concrete is more durable and less heat sensitive but has to be laid in sections, which can make for a bumpy ride.

"The concrete is a little bit chalky and dusty when you get on it when it is early in the weekend," Earnhardt explained. "Our hot tires pick the rubber back up off the concrete, more so than the asphalt. Of course you never know, asphalt being as dark as it is, it's hard to tell. It is just not a real good race track surface in my opinion. It lasts a long, long time but it gets rough. It's just not the preferred surface for building a race track. They [seams or joints] don't mess you up; they just become annoying and rough. The concrete gets real rough as it cures over time. It becomes very rough."

Earnhardt is fourth in the standings, 47 points behind the leader, Carl Edwards. He is a former Dover winner, driving to victory here in 2001. It's been nearly 10 years since that last triumph, but Earnhardt is upbeat entering Sunday's race.

"I feel good this weekend," he said. "No reason why we shouldn't run good this weekend -- been running good every weekend. So, I feel pretty confident that we will keep up at least our current performance; hopefully better."

When it comes to mastering the Monster Mile no driver does it better than Jimmie Johnson, who has six victories, eight top-5 and 12 top-10 finishes in 18 starts. He swept both Dover races in 2009 and drove to victory at Dover last September.

Johnson is so good at Dover, the track is honoring him with "Jimmie Johnson Day" on Sunday.

"I hope to reward myself with a win on Jimmie Johnson Day -- that would be pretty awesome," Johnson said. "I'm definitely honored to have that bestowed upon myself and have it be Jimmie Johnson Day and I'd better make the most of it."