Originally Posted by TcBish
Sweet thanks for that. So I know if I go over 3" I run into major upgrades. What about if u run a 3 lift with 1or 2 body also or do I run into the same problems.
In general, body lifts are frowned upon with JKs. With a 3" suspension lift and flat flares, you could easily fit 37" tires. Maybe even 40s. Those are enormous. That means that unless you're just doing it "for looks," there's really very little reason to add a body lift.
But let's back up a bit . . . any lift, whether a suspension lift or a body lift, changes the geometry of the vehicle in some fashion.
If the lift is big enough or the adjustments you make to compensate for the geometry changes are crappy enough, you'll have problems.
Suspension lifts move the frame and body upwards while the axle stays in place. The result is geometry changes (and therefore potential problems) with anything that connects the frame/body to the axles. Driveshafts, control arms, trackbars, and brakelines are the most commonly discussed areas that may need to be adjusted or replaced to compensate for the change.
Body lifts move the body off the frame. That can cause it's own problems with anything that connects the body to the frame--your transmission and transfer shift sticks are suddenly too short, your steering linkages are not operating at the angle they were meant to, your bumpers (attached to the frame) don't touch the jeep body anymore and an unsightly gap appears inside your wheel wells where you can see the body no longer sits on the frame, etc.
Just like with suspension lifts, there are ways to compensate for the geometry changes caused by body lifts . . . but they don't always work perfectly and sometimes you have to compromise or you'll have other issues.
For these reasons, it is usually advised that suspension lifts are kept 3" and below, and body lifts are kept 1.25" and below. There are plenty of options that are bigger, but you have to be prepared to open your wallet to fix the issues you're likely to encounter if you use them.
If you must add a body lift, I'd keep it at 1". That means you'd have 3" of suspension lift and 1" of body lift, and that is plenty to run 35" tires. In fact, many would think that any more than that will make 35" tires look too small.
: Here's a thread from another forum
showing a number of JKUs with 4" of lift and 35" tires. Unless somebody is looking very carefully, 4" of suspension lift will look the same from the outside as 3" of suspension lift plus 1" of body lift. Note that many in the thread post pics of their 3.5" lift with 35s. Many folks just run a 2.5" lift for 35s.