Re: 4\" Lift, 33 tires : do I need Bump Stops ?
Short answer no, but heres what you do. Leave the stock ones on. Run a tire up a ramp or convenient rock until you are either at full compression or about to make contact with a fender. Now take a look underneath, see where your axle is compared to distance from the bumpstop, and adjust the stop accordingly using 1" square tubing. I had to drop mine 1". Those extended bumpstops not only look stupid, they are stupidly expensive and are generally longer than you need.