With the RK 2.5 I started with about 3" to 3-1/4". It sagged out pretty hard in a year. Lost enough that pot holes and dips would bottom out even after I added sone daystar 3/4" coilspacers. (Combo of shocks, fat jk loaded with my carpentry tools and too light a spring maybe)
Went to a slightly longer fox and the metalcloak, (stiff shock, stiff spring. I like it, but it isn't a super plush ride, more truckish) net lift is about 4-1/2". It has been over a year and it might have settled a bit, but not much.
Just note that in the second pic, my passenger side is up a couple inches on the curb.
For the op: there are many people who run 35's with flat fenders and either no lift or coilspacers for mild wheeling. It all depends on your intended usage. Flat fenders are kites at highway speeds, your milage will decrease more with more lift , and your roll center may raise depending on how you modify your geometry.