Page 69 and 72 of the information kit for a 1946, https://www.gmheritagecenter.com/do...hevrolet-Trucks/1946-Chevrolet-Truck.pdf has all the information on springs. The deflection rate is the same as spring rate, 1" compression for every 100 lbs applied. 1946 1/2 has a 260 lb spring rate. Be sure to ask what the new ones have. The higher the rate, the stiffer the ride.