Torsion Bar Settings

[dudecw]

I just bought a 1960 GMC Suburban. The truck has been lowered by the previous owner. I like the result just not the method. He heated the back springs with a torch and just loosened the torsion bars on the front. I am going to fix the front by installing 2.5" drop spindles and putting the torsion bars back to stalk.

My question is, how do I know how much to tighten the bars? Is there a factory setting that I can put them back to?

Thanks for the help!