[robnolimit]

OK, lets think about spring rates. First, we need to imagine our basic truck, and how we want it to sit. I'll say that we have a trailing arm C10 shorty, dropped 4", no notch. There is now 4" from the axle housing (top) to the frame rail (bottom). So, from Ride Height (RH) we have 4" of compression travel available. - then it bottoms out. I'll also say that our truck weighs in at 3850 lbs. with 1400 lbs on the rear (JT's specs.). Looking at the rear only, thats 700 lbs per side. If you had a 400 lb/in spring, it would take 1600 lbs per side to bottom the truck out, 3200 lbs total. (appx 1600 lbs and a good bump would do it) But this will still haul a 1/2 ton load. Now if we put 200 lb springs on it, and get the same ride height it would reasonably only carry 800 lbs without bottoming out to bad. Remember that appx 1/2 of the driver/passanger weight will go to the back. So now your down to about 600 lbs load cap. - max, with 200 lb/in springs.