Just out of the United States Marine Corps, Liberati started his racing career by building chassis for Hutcherson-Pagan in 1986. In 1991, Liberati joined Roush Racing as a team mechanic for Wally Dallenbach. Two years later, he became the shock specialist for Michael Waltrip at Bahari Racing.

Liberati returned to Roush Racing in 1995 and played the key roles of car chief and shock specialist for driver Jeff Burton's newly formed No. 99 NASCAR Winston Cup team. Liberati remained there for two years before joining Hendrick Motorsports as a car chief for the No. 50 Chevrolet. Following a successful stint at Hendrick Motorsports, Liberati was handpicked to direct the start-up effort of the Herzog Jackson Motorsports team.

Liberati, a native of Bellaire, Ohio, led the No. 92 Excedrin Racing team to one victory, four top-five and nine top-10 finishes during the 2001 season with driver, Jimmie Johnson.

After teaming up with veteran driver Todd Bodine in 2002, Liberati led the team to its second victory, at Kentucky Speedway in June, as well the first Busch Series pole position in the history of Herzog Jackson Motorsports at Chicagoland Speedway in July. Under Liberati's tutelage, the Herzog Jackson Motorsports team became a force to be reckoned with each and every weekend.

During the 2004 season, Liberati worked with Roush Racing as crew chief for the No. 9 Pennzoil Ford, in the Busch Grand National Series, with drivers Mark Martin, Jeff Burton, and 2003 Winston Cup Champion Matt Kenseth.