4/6 lowering kit on 275/45/20

[avilleg0]

Hey guys just finished with 4/6 drop on my truck and i have boss 338 wheels 8.5'' in the front an 10'' in the back 275/45/20 all around. My problem is that the rear tire hits the rear lips pretty bad already trimmed half off the lips already and don't feel comfortable trimming any more. anybody think that if i run a slight less taller tire i can get away from this situation thanks . ps i tried to change the bolt holes on the shackles to the lower ones to see if i could get any more lift it did help a little