About 5.7 litres
Depends on what engine a 1972 dodge challenger has...
The 2010 Dodge Challenger's engine produces 250 ft-lbs. @ 3800 rpm.
The 2008 Dodge Challenger's engine produces 420 ft-lbs. @ 4800 rpm.
The 2012 Dodge Challenger's engine produces 268 ft-lbs. @ 4800 rpm.
The 2013 Dodge Challenger's engine produces 268 ft-lbs. @ 4800 rpm.
The 2009 Dodge Challenger's engine produces 250 ft-lbs. @ 3800 rpm.
The 2011 Dodge Challenger's engine produces 268 ft-lbs. @ 4800 rpm.
The 2014 Dodge Challenger's engine produces 268 ft-lbs. @ 4800 rpm.
Depends on which engine you're referring to, as there were several engine options for the Challenger in 1970.
Depends on engine
Depends on engine, transmission, etc...
that all depends on it's condition and engine option.