i just used my shims that were on there before and didn't even bother with the preload. pretty stupid i'm sure but after about 8K miles nothing seem to be going wrong. my alignment was near perfect (until i went in a huge ditch at 30MPH) and even now it's pretty good after the lady at the counter said "they did the best they could but with those wierd ball joints it was kinda hard to work on" i just kind of laughed and said i would come pick it up. oh and i still have the shims from the marlin kit i bought and some of the gaskets and seals which i may need to replace after having gone in the ditch.