Mark Dudley Jr. runs low 6s in the eighth with his 700+ HP Blackbird Hemi just as a reference point. The 600+ HP Blackbird package plus a Prefix intake (or wait for the Blackbird intake to come out) might get you close your goal.
Dudley’s Blackbird Performance 6.4L-Swapped '74 Plymouth Duster Runs 6.0's - Mopar Connection Magazine | A comprehensive daily resource for Mopar enthusiast news, features and the latest Mopar tech