Modern Drivetrain Swap

Looking at swapping in a modern hemi, trans, suspension and interior into my 71 Challenger.

I don't have a motor, trans, engine bay harness, radiator, driveline, rear gear set, or much of the interior stuff sans the dash and panels. So you can see why this particular swap would work good for me.

Trying to decide between using the unibody sub floor from the lc/lx, or to take the rear IRS and front suspension and swap those in my car.

Anyone have experience with either option?