David, sorry it took awhile to get back to you. My new springs were made by Detroit spring. I borrowed a set of digital car scales and made a ton of checks to know just what I was dealing with, starting with all four corners with and without passengers ( driver to ), full tank of fuel, road ready so to speak. Then I lifted the truck up on stands and dropped the leaf springs at one end to measure the weight of axles, tires, brakes, and steering. With half the springs dropped and all the axle weight on the scales, the actual spring weight was split between sprung and unsprung weights. This let the spring guys know what the leaves were actually carrying. I then removed one front and one rear and made a makeshift spring tester using my Toyota for weight, and one digital scale. With solid roller bearings at each end of the leaf spring rolling on smooth concrete ( think of funny look skateboard ), I lowered the trailer hitch of the Toyota down on the scale which was setting center point of the leaf. Leaf spring rates are measure by how many pounds it takes to compress the spring 1 inch. With some steel rulers and careful control of the jack, I was able to get a fairly accurate front spring rate of 360 to 370 pounds per inch of compression. This is way less then the 475 it came with. My new springs are in the 275 range,much lighter, more give, better ride! I can get away with this due to the later model 250 weighing much less the 216 it came with and the fact GM under rated the load carrying capacities. The rear springs are about 2/3 of what the OEM spring rates are.
As far as shocks and the ride, I still feel they are to stiff for slow speeds. At highway speeds, 55 to 75 the truck handles the bumps like they are not there, it rides as good or better then my '03 Tacoma, but at slow speeds 40 and down, the front bucks up and down over every spot in the road, like the springs are still to stiff. I know they are not, so the shocks have to be holding to tight. My next move is to unhook them and go for a short drive on my local test track I have around my area. I picked roads close to home and travel the same direction when testing stuff. If the front stays steady and the springs take the bumps, then I know for certain the shocks are to stiff. If thats true, then I have to shop a different manufacturer or model, I don't really know what the next step will be. I am also looking at replacing the tires. They are 19 year old radials, garage kept, still half tread or more. The age is starting to worry me a bit. I also run 40 psi in the front to make it steer easier, so I have that to play with.
I am hoping new tires with less air will help and I don't have to mess with shocks, but the easy way never works out for me.
