From the outset, the 5.7-liter HEMI is substantially smaller than the 392 (6.4-liter) V8, and typically makes less power. The old adage "there's no replacement for displacement" applies here.
As a result, you can no longer get a 6.4-liter Hemi V8 with 475 hp (354 kW / 482 PS) and 470 lb-ft (637 Nm) of torque. Instead, your options are limited to a 5.7- or supercharged 6.2-liter V8.