The K&N Pro Series East (formerly Busch East Series & Busch North Series and Camping World East Series) is a regional stock car racing series owned and operated by the National Association for Stock Car Auto Racing (NASCAR).

Races are held at oval tracks ranging from 1⁄3 to 1 mile (0.54–1.61 km) in length and on two road courses, 1.53 and 2.45 miles (2.46 and 3.94 km) in length. Most races are stand-alone events (i.e. not in conjunction with other NASCAR touring series), but there are three race weekends that are in combination with the NASCAR Cup Series.

Many of the NASCAR Pro Series East drivers on the series are gaining experience with the hopes of moving up to one of the major NASCAR series, however some of the drivers are right at home in the series and have no plans of moving on. The series is not only developmental for drivers (including Joey Logano, Martin Truex Jr., Ricky Craven, Mike McLaughlin, Austin Dillon, Trevor Bayne, Brian Ickler, Ricky Carmichael and Ryan Truex), but for crew members (such as Greg Zipadelli and Marc Puchalski) and officials, as well.

In 1994, it became the first NASCAR-sanctioned series to have a winless season champion when Dale Shaw won the then-Busch Grand National North Series championship without winning a single race all year. The series had the distinction of being the only NASCAR series in which this had happened until 2013, when Austin Dillon won the Nationwide Series championship the same way.^[2]

The other regional division at the Grand National level of NASCAR is the K&N Pro Series West.

Formed as the NASCAR Busch Grand National North Series in 1987, the series originally raced primarily in the Northeastern United States, including Maine, New Hampshire, Vermont, Massachusetts, New York, New Jersey, Connecticut, and Pennsylvania. Drivers in the series could compete in "combination" races with then named Busch Grand National Series (now Xfinity Series) that were held at various tracks over the years, including but not limited to Daytona International Speedway, Nazareth Speedway, Watkins Glen International and New Hampshire Motor Speedway. Combination races were on the schedule until 2001. In 2002, a big crash occurred at the Glen that saw many cars spinning through the esses on lap one, along with Troy Williams actually overturning over the guardrail. No one was hurt.

Over the next 18 years, the series extended its reach and added races in Delaware and Virginia. The series name was changed to Busch East for the 2006 season after a race was added in Greenville-Pickens Speedway in South Carolina. Races were added in South Boston, Virginia, and Nashville, Tennessee for 2007 to continue the push South and West, as well as East-West combination races at the Iowa Speedway in Newton, IA and Elko Speedway in Elko, MN.. The 2008 schedule had the series running races in 8 states up and down the East coast. (Connecticut, Delaware, Iowa, New Hampshire, New York, Ohio, South Carolina, Tennessee and Virginia)

In 2003, NASCAR unified the rules of the West Series and North/East Series to a single rules package. A post-season invitational race known as the Toyota All-Star Showdown was also added to pit the best drivers from both series head-to-head.

For 2007, NASCAR made several rule changes including giving team the option of using "spec" engine and a composite body to reduce the cost of competing in the Camping World Series. The "spec" engine has become fairly popular, but the old style steel bodies are still preferred over the composite bodies by most teams.

On December 16, 2007 NASCAR announced that Camping World would take over as title sponsor of both series in the Grand National Division.^[3]

For 2010, the names of both the East and West series were both sponsored by K&N Engineering and the East Series was named the K&N Pro Series East. In 2011, NASCAR lowered the age minimum across each of its regional touring series to 15.

As part of NASCAR's unification of the two Camping World Series in 2003, the cars can be either a 105-inch (2,700 mm, which had been used in the former Busch Grand National East) or 110-inch (2,800 mm, which had been used in the former Winston West) wheelbase. Cambered/off-set rear ends are not allowed.

Currently, the series requires the use of a Five Star bodies composite body that started in the 2015 season, currently the 2013 Holden Commodore, Ford Fusion, or Toyota Camry. Since the 2007 debut of the new chassis at the Cup and 2010 debut at the second-tier level, many K&N Pro cars are old Cup or Xfinity cars.

Teams have an option of building their own engines or they may run a specification engine, similar to what is used in many short tracks. Both engines are V8, pushrod, 12:1 compression motors. "Built" motors are built to team specifications using any configuration of pieces as long as it still meets NASCAR specifications. The spec engine is built using NASCAR-Approved pieces that may be purchased from an approved supplier. The engines may be purchased as a kit or pre-assembled. All of the spec pieces are individually encrypted with a barcode for verification and tracking purposes and can be checked during the inspection process with an encryption reader. NASCAR has a specification supplier for the series-specification engine.

When the series first started, the cars ran a V6 engine with a maximum 274 cu in (4,490 cm3) displacement and no compression limit. In the early/mid 1990s the V8 engine with a 9.5:1 compression and maximum 358 cu in (5,870 cm3) displacement was introduced to the series as an alternative to the V6 engines. Due to the decrease in popularity of the V6, it was phased out for the 1999 season. When the East and West series rules were combined, the compression ratio changed to 12:1.

K&N Pro Series cars use Sunoco racing fuel, NASCAR's specification fuel. For races run with national series, the cars run an E15 blend since the national series uses such fuels. Starting in 2018, cars will use radial tires. Along with NASCAR's international series, the K&N Pro Series have General Tire as their exclusive tire supplier.^[4]

^[5]

On November 4, 2014 at the SEMA Show in Las Vegas, NASCAR president Mike Helton unveiled a new body style for the K&N Pro Series based on the NASCAR Cup Series Gen 6 models. The new body, developed with Five Star Race Car Bodies, is constructed of a composite laminate blend and designed with easily replaceable body panels, expected to shrink the costs of fabrication dramatically. The body style is eligible for use in both K&N Series competition and ARCA Racing Series competition for the 2015 season, replacing the old Gen 4-style steel bodies after 2015, and the current one-piece composite body after 2016.^[6]

In 489 races there have been 120 different winners, 67 of which have won multiple races. Does not include Combination race with Busch Series drivers won by Busch Series drivers since these victories are already counted in the Busch Series. Updated after: Who's Your Driver Twin 100s (May 5, 2019)

All-time wins under K&N Pro Series East banner. Does not include the combination races with Busch Series because the drivers who won those races are computed as Busch Series winners.