Lowering on 19's or 22 ?????????

they are 245-40-19's( they clear fine) , the problems with the fender happen when I stick the 16" stockers back on with load rated tires.clearance is a little tight while driving when the nose bottoms out with the static 5-8 drop, had to roll for more clearance.
I still would like to roll with some 20's, better tire selection