A 1.5" lift (or just 1.5" bump stop extensions on the front) is recommended for clearance to the motor mounting brackets on 3.6 V6 JL models from 2018-2020. JT 3.6 V6 and JL 3.6 V6 model year 2021 and newer can typically be run without any lift or bumpstop extensions. No lift or bump stop extension is required for the 2.0 I4 engine, 4xE, Diesel or 392, however we do suggest cycling your suspension and testing your bump stops each time you make a change to the configuration of your vehicle.