Zipadelli received his release from Joe Gibbs Racing earlier this week. He's been crew chief of the No. 20 at JGR since 1999 and spent 10 years with Stewart.
Zipadelli guided Stewart to the NASCAR championship in 2002 and 2005. He has spent the last three seasons as crew chief for Joey Logano.
JGR then selected Jason Ratcliff as the new crew chief for Logano.
Ratcliff spent the last seven years as crew chief for JGR's No. 18 Nationwide Series team. He led that team to 30 victories and the owner's championships in 2009 and 2010.
Stewart has been without a competition director since early summer and has long believed to have been holding out for Zipadelli.