Big Block Suspension Question

In the very early stages of resto right now, putting new brakes in to get it road safe.

But in doing the brakes, the suspension might as well be changed. We plan on doing a 440 swap down the road. On a scale of "almost useless" to "absolutely necessary", where does changing the torsion bar suspension to a coil over conversion lie?

For information, it's a 67 Barracuda that will be almost exclusively street driven, with occasional track days.

Thanks in advance.
Personally I would stick with a potent small block stroker big blocks are nose heavy, a friend on mine had a 67 dart with a 440 it did not handle all that well your call