What's the least amount of money I could expect to pay for 4" rear leaf springs only that are not total pieces of junk. I don't need shocks or anything. I have blocks, and even after remilling the blocks to a better pinion angle, my stock rear shocks are sagging so bad I just can't get the vibration out. The pinion angle is just jacked up. Plus, after milling the rear blocks the rear sags ever so slightly... maybe 1/2 ich or so.. but it's visible to me and i hate the BULLDOGGED look on my K5. Do 4" leaf springs come or require shims?