Very much so. I don't recommend anything under a 1" torsion bar, the reason the stock torsion bars were so soft had a lot to do with the original bias ply tires and shock technology at the time. Now with even a half decent set of radials and mediocre shocks you can have better ride quality than original even with significantly larger torsion bars.
The 1.03" PST bars are a good upgrade, a lot of people here run them. They're stiff enough to lower the car some, significantly improve handling and not rattle your eyeballs loose with a good set of shocks. They're probably still too soft if you're building a car for autoX, road racing or even just aggressive street handling. But for a street car that has a slightly lower ride height with improved tires and braking they're a great choice.
