Recurved leaf springs

The question is whether they need it. My guess is yes, but that would be because of loss of rate (overloaded and cycling). Factory springs (except SS) are designed to be flat when loaded. So with full tank and and say 100 pounds of tools or luggage in the trunk, flat would be correct. When removed, they both should have the same arch, and you can also measure the free hieght and how much the move when loaded. Used the way the OP described by guess is they will not be the same free arch...