The block is aluminum as well. I'm not looking to drop money on new torsion bars just to do it, I would just rather do it now since everything is already ripped apart. I just didn't know if they wear out that much considering they're now 50 years old.

A 1.00 inch torsion bar is 50% stiffer than a 0.900 bar. Spring rate for torsion bars is diameter to power of four so a small change in diameter makes a big difference.
The rule of thumb for street handling is to have the bar rate be 10% of the front end weight. Typical E/B body car has about 1800 lbs up front so a 180 lb rate bar is recommended which is a 1.00 inch bar.