That 2.5" leveling kit is all you need to clear 35's on stock rims, rear doesn't need anything. I personally had the autospring 2.5" leveling kit and their 3" rear block that replaced the stock 2" rear block. The 3" rear block wasn't needed to fit the 35's but was more so personal preference. Keep the 2.5" leveling kit you have now and what you do to the rear (keep it stock, add a leaf, or taller block) is up to you. Once again, SEARCH the forum as there is a ton of info on this subject

I have an 05 Fx4 with a 2.5 leveling kit, but I was wondering if I needed to put a 3 inch in the front to fit 35's and what to put on the rear.

04-08 4x4 can fit 35's on stock rims or some after market rims with a 2" leveling kit with minimal rubbing at full turn. Do some searching on the forum, lots of info on this subject

Hey man what kind of lift did you put on to fit the 35's on the factory rims?