I'm in the process of stuffing a 160x60x18 in my '02 Softail Bobtail fender.
Had to cut 3/8" from the caliper axle tube, (frame side), machined .165" additional clearance from the anti-rotation relief cut in the caliper, added 3/8" longer wheel spacer to the left side, and spaced the sprocket/pulley 3/8" to the left to put it back in line with the trans.
Mock-up looks good. Trick is in the "profile" / 60, and playing with the suspension, (up/down). Also want to turn the fender strut bolts around so the heads are inside the fender to maximize clearance availability.