Petty and his car seemed unbeatable, something that did not sit well with NASCAR boss Bill France, who wanted all racing equipment to be as equal as possible. The Hemi engine threatened this balance and it was banned for the 1965 season. Indignant with what they felt was an arbitrary decision, Chrysler's brass pulled their cars out of NASCAR competition. With no other venue open to him, Petty went drag racing in a Chrysler-sponsored Hemi-equipped Plymouth Barracuda named, appropriately enough, Outlawed. The oval-track champion enjoyed some success in quarter-mile (400 metre) competition before returning to NASCAR later in the year when poor attendance forced France to reinstate the Hemi.

ALTHOUGH by then Petty was enshrined as a fan favourite, he would occasionally fall out of favour with NASCAR management. Their differences came to a head in 1969 at the inaugural running of the Talladega 500. The lengthy 2.7-mile (4.3-kilometre) track surface combined with the 200 m.p.h.-plus (320 km-h) racing speeds were prematurely destroying race tires, making conditions dangerous. Most of the top drivers, led by spokesman [Richard Petty], informed Bill France they were boycotting the race. Neither side backed down and the event was held with a rag-tag field of independent drivers and also-rans competing. The Talladega confrontation made a hero out of Petty who was lauded for taking such a controversial stand.

Petty's winning ways also came to the attention of the STP Corp. After Chrysler cancelled its backing of Petty Enterprises in 1971, STP stepped in as a major sponsor. As a result, the traditional "Petty Blue" race cars were partially painted in STP red. This marked a first for this type of prominent corporate sponsorship, something that's accepted as commonplace today.