CALENDAR OF EVENTSThe Mopar 2007 HEMI Challenge Race Series Expands CENTER LINE, MI (May 9, 2007) - With an increasing number of events and competitors, organizers say the HEMI Challenge continues to grow from its beginnings as a one-race event. The HEMI Challenge race series spotlights 1968 Plymouth Barracudas and 1968 Dodge Darts from the NHRA Super Stock/A-HEMI (SS/AH) division.