OK, So I am doing some research for a buddy of mine.
he just got a used 2012 F150 FX4. He knows nothing about the truck or anything the previous owner may have done to it.

It's got 295/70r18 Nitto Terra Grapplers on factory 18" wheels. I took a brief look around the suspension and can't figure out if it's been leveled or not? (it was nighttime and parked on an incline)

It has rancho shocks all around. (not sure what model) The rear has the 1" rear spacer under the leafs, looks stock.
But the front doesn't seem to have a spacer, but I don't know if the previous owner upgraded to longer front struts?

Could that size tire fit on a stock FX4? or would you assume it has already been leveled? Or, do you know the factory measurement of an FX4 from the hub to front top wheel well?

I know it's a shot in the dark, just thought id ask anyways. I will swing by and get some measurements and pictures later this week.
Thanks in advance

 

sounds like your buddy has the rancho quicklift up front, which would be about 2" of lift. The rear blocks under the leaf springs are factory. Most likely that tire size (which is about a 33.8x12.00) wouldn't fit unless the truck was leveled.

 

Thanks!
That's what I was thinking, I am going to get a better look at it tomorrow.
If that's the case, What are the cons of adding a 1" spacer on top of the Rancho Quick Lift?...and possibly a 3" block in the rear to replace the factory block?

 

The cons for the front would be severe suspension angles. With quick lifts raising it about two inches and an added spacer on top of that, you'll wear through and ruin front end parts and you'll have a very stiff ride. That's if you can even get every to bolt back together with a spacer on top of the quick lifts. The largest spacer I'd even consider putting on top would be a 1/2" spacer. But in all honestly, I'd leave it as is.

You'd need a real lift, not a level if you want to go higher.

Adding a larger rear block won't effect much.