i dont bother with re-arching, think its a waste of time and money, they have sagged to where they are for a reason. what ive done for the last 35 years is to get another identical, or close set of springs, cut the curls off the main leaves and put the main in just under the main [orig] and the first leaf of the donor in then the rest of the orig spring pack; this lifts the car about 2 is inches and greatly increases the rate and makes for a great set of springs that will never sag a bit and work very well, for many years. just one [very cheap] mans solution to the throwing money at springs dilemma.......... JEFF tucson az.