I recently moved from 7K to 8K springs at all four corners, and there was no degradation of DD ride quality, so I'm thinking of trying 9K springs. One minor concern I have is getting the correct amount of droop travel at the rear. 8K springs only required about 5 mm of preload to get the correct droop travel at the rear. I'm guessing that 9K at the rear will require 0 mm of preload. Is there any issue with having 0 mm of preload, e.g., having just enough preload to keep the spring from rattling around when the rear wheels are off the ground?