Re-arcing mopar SS leaf springs?

The place we have here In Lincoln nebraska used to be in-line suspension. Inland truck parts bought them out. But they still do all the speciality suspension work around here. Im not sure how they do there re arching on leaves. Id guess with a press because in the past I don't remember them looking like they were ever heated up at all. When they were on my friends car they were not flat but had just a bit of curve to them. His new same part number SS springs have an arch to them for sure installed.