Which torsion bar to use?

Bill Crowell said

72Valiant4Door, I am not sure if I agree. If the spring rate is too high, the tire won't stay in contact with the road over irregularities

YES, BUT WHAT DEGREE IRREGULARITY, AND TRUTHFULLY WHAT KIND OF AGGRESSIVE
DRIVING?
Porsche is an example of a good-handling car with a relatively low spring rate.

Click to expand...

Now you're comparing apples to Gucci loafers, and I guarantee the rear bars are not a
"relatively low" rate. Which Porch? There's plenty of variety there as well.

Seriously, nothing smaller than a .910 bars & a decent 1" stab. bar w/a V-8 in that car if
it's all there and all steel. I went .890's, but it's a six that's having a weight reduction/re-
distribution program. Your biggest challenge will be to find tires up to the task in 15"

This topic has been bludgeoned over and over, the above is a competent compromise
between street manners and cornering, and works well on real roads not tracks.