Stock diameter is 29.5", the Defenders have a diameter of 30.8", so your bringing the tire 3/4" (approximately) closer to the steering knuckle. Starting to get onto dangerous ground, IMHO.
If someone, somewhere, somehow could come up with a sticky chart breaking down 'possible tire fit' by "Wheel Size", "Body Lift Needed?", "Suspension Lift Needed?", "Spacers Needed?" and "Custom Mods Needed?" those of us who aspire to go for lifts/tires may be able to quit asking about our...