I have a 2009 fx4 super crew. looking at getting bilstein 5100s and 295/60/20 trail grapplers on factory wheel. my question is will i have to set the bilsteins at the highest setting or can i go a little lower? also thinking of getting new wheels 20" with 5.71 in of backspacing think they are 18mm offset was wondering if that will still work if i decide to get the new wheels? Any help appreciated