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.
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.
i have QA1 tortion set up on my 68 with small block. They have a new set up with coil overs and it is awesome. Set up for big block too. Now a rear coil over is available from them.
Just installed it and love the performance and tuning capabilities.
Not cheap though.