I may be mistaken but I believe I've read on some Tire and Wheel Fitment sticky thread that a 2.5" level on a 2wd is not enough to clear a 35. A 2.5 on a 2wd will clear 33-33.4/5" tires

A 2.5" level on a 4wd will fit a 35, easy.

A few options that I've found for us 2wd truckers:

BDS 2wd suspension lift kits here

A potentially cheaper option is to find a set of 4wd front strut assemblies and 4wd shocks for the back, and swap those in place of the 2wd components. Simply swapping the front components will net approximately a 2" taller front end. Then put a 2.5" level kit on the front and AAL or 2" or larger block kit in the rear and the truck will be setup like a 4wd F150 with a 2.5" level - thus, clearance for the 35s

Anybody, please feel free to chime in if I'm mistaken

 

Might want to check with a local shop. I was able to run 34.5" tall tires with a 2.5" But it took some trimming to fit on a 2WD. Keep in mind that a 4WD F150 is 1/2' higher from the factory.

If he doesnt feel good about trimming the the fender liner or plastic front lip, he might not want to run 35s

Also, the offsets are going to crucial to know. I was running a 18x9 wheels with -12 offsets.

 

Call Land O lakes 4x4!

 

4x4 models are actually (on average) about two inches taller, both front and back. I know the 2012 FX4 comes with a 1 3/4" block in the rear. That's not including whatever extra height the 4x4 shock gives. My FX2 has NO rear block at all and when parked next to a leveled FX4 it's beyond easy to spot the height difference