If you're running stock torsion bars, you need to run the factory ride height unless you want to constantly be on the bumpstops. The method they used measured from the LCA to the ground, and A body falls under the "V and L" line in the manual. This is the factory method...
Even at the factory ride height, with factory bump stops, you'll be hitting the bumpstops with stock bars. That's why they're that triangular shape, the bump stops were used as part of the suspension travel.