Allmendinger: Indy 500 will be 'big challenge' for Kurt Busch

NASCAR has been a tough nut to crack for any number of open-wheel racers who moved to stock cars in recent years.

Danica Patrick has never finished higher than eighth in 52 career NASCAR Sprint Cup Series starts, while Juan Pablo Montoya, a past IndyCar champion, Indianapolis 500 winner and Monaco Grand Prix winner, never won a Sprint Cup race on an oval track and had just 24 top-five finishes in 253 starts. Likewise, former Formula One racer Scott Speed only had one top five in 118 career Cup starts.

With Martinsville winner Kurt Busch getting ready to do the Indianapolis 500/Coca-Cola 600 double, one driver who has a unique perspective on the challenges that await Busch is AJ Allmendinger.

Allmendinger, who drives the No. 47 JTG Daugherty Racing Toyota in the Sprint Cup Series, came up through the old CART open-wheel series, moved to stock cars, and last year drove six races in what is now known as the Verizon IndyCar Series and 18 more in Cup.

Busch will drive for Andretti Autosport in the Indianapolis 500, and Allmendinger said the race will push Busch's prodigious talents to the limit.

"Kurt going to Indy being at Andretti, he was fast at his rookie orientation," said Allmendinger, who won five of 40 starts in CART. "He's a hell of a race car driver. So I think he'll be fine ... The only thing is, just the way those cars race at Indy compared to driving by yourself, it's a lot different. And I spent a lot of time during the month of May last year trying to learn how to be in traffic. And heck, I even went into the race still wishing I had more practice. So that's a big challenge. But I think he'll be fine. He can wheel a race car, for sure."

Allmendinger said it won't be easy for Busch.

"I went back there and the series is so difficult from top to bottom," Allmendinger said of the open-wheel racing, where he had a best finish of seventh in last year's Indy 500. "And for me, it was just hard to go and try to run top 10 and figure out how that is. So it's not easy just to jump back in and do it."