FILE - In this Feb. 18, 2017, file photo, Kurt Busch sits behind the wheel as he prepares for NASCAR auto racing practice at Daytona International Speedway in Daytona Beach, Fla. Monster Energy is set to start a two-year sponsorship deal with a two-year option worth a reported $20 million annually _ a staggering discount from the $750 million, 10-year deal Sprint had paid NASCAR to have its name emblazoned in the title series. (AP Photo/Terry Renna, File)
Denny Hamlin, right, signs autographs for fans as he walks to his garage at a NASCAR auto racing practice session at Daytona International Speedway, Friday, Feb. 24, 2017, in Daytona Beach, Fla. (AP Photo/John Raoux)
Jimmie Johnson, left, talks with a team member outside his garage during a practice session for the Clash NASCAR auto race at Daytona International Speedway, Friday, Feb. 17, 2017, in Daytona Beach, Fla. (AP Photo/Terry Renna) **FILE**
FILE - In this June 30, 2016, file photo, Dale Earnhardt Jr. gestures as he speaks during a news conference before the start of a NASCAR Sprint Cup auto racing practice at Daytona International Speedway, in Daytona Beach, Fla. NASCAR has a new sponsor, a new format and a familiar face this year in its bid to rebound from declining ratings and attendance. The next 11 months will show if Dale Earnhardt Jr., Monster Energy and different rules can provide the needed jolt.(AP Photo/Wilfredo Lee, File)
FILE - In this Oct. 7, 2007, file photo, a Confederate flags fly in the infield as cars come out of turn one during a NASCAR auto race at Talladega Superspeedway in Talladega, Ala. NASCAR is backing South Carolina Gov. Nikki Haley's call to remove the Confederate flag from the South Carolina Statehouse grounds in the wake of a massacre at a Charleston church, it said in a statement Tuesday, June 23, 2015. Though NASCAR bars the use of the flag in any official capacity, many fans fly the flag at their races. (AP Photo/Rob Carr, File)
1969 FORD MUSTANG BOSS 429 - was a high performance Ford Mustang variant offered in 1969 and 1970.The Boss 429 (also known as the 'Boss 9' by enthusiasts) is arguably one of the rarest and most valued muscle cars to date. In total there were 859 original Boss 429s made. The origin of the Boss 429 comes about as a result of NASCAR. Ford was seeking to develop a Hemi engine that could compete with the famed 426 Hemi from Chrysler in NASCAR's Sprint Cup Series (then known as "Grand National Division"). NASCAR's homologation rules required that at least 500 cars be fitted with this motor and sold to the general public. After much consideration, it was decided by Ford that the Mustang would be the car that would house this new engine. The Boss 429 engine was derived from the Ford 385 engine. It used four bolt mains, a forged steel crank and forged steel connecting rods. The engine featured aluminum cylinder heads, which had a modified Hemi type combustion chamber which Ford called "crescent". These heads used the "dry-deck" method, meaning no head gaskets were used. Each cylinder, oil passage and water passage had an individual "O" ring style seal to seal it tight. The Boss 429 engine used a single Holley four barrel carburetor rated at 735 CFM mounted on an aluminum intake manifold that flowed well for its time. 1969 cars featured a hydraulic lifter camshaft while 1970 models got a mechanical lifter camshaft along with an improved dual exhaust system though rated power output stayed the same.
Tony Stewart smiles as he sits in his car before qualifying for Saturday's NASCAR Bank of America Sprint Cup series auto race at Charlotte Motor Speedway in Concord, N.C., Thursday, Oct. 9, 2014. (AP Photo/Terry Renna)