what size torsions for a 69 dart for a little better handling?

The first set of .890" bars I bought came with some other '67 Barracuda parts. The bars had 900 miles on them and I paid $100 for the bars, complete dash, and a couple of small items. The second set cost a bit more, but I recall it still being less than $100. The two big block sway bars cost me $20 and $40. If I were out buying new parts I would probably go with the PST 1.03 bars.