Looking at doing a level kit and wheel/tire upgrade on a 2014 FX4. Anyone know whether a 1.5" or 2" level is better, and I'm looking at 305 R55 Nitto G2. Anyone know if I need to worry about rubbing or issues with larger tires? Thanks for any advice

 

A 305/55/20 will probably work on either a 1.5" or 2" level. That said, most leveling kits are 2", which is what I'd recommend.

For reference, I have 285/65/20s and don't rub at all.

 

I haven't upgrade my tire size yet. I have a 14-FX4 w/1.5" AS Leveling kit. you could go with 1.5" or 2" probably not notice a difference. MY neighbor has a XLT 12, w-2" and 295's with no rubbing.
soon as my tires wear out this year, I will be going with 285's or 295's GY - DT's on stock wheels, or 285's with Raptor 17" wheels.

another huge improvement is changing the rear shocks to at least some Bilstein 5100's
doesn't change the height, but it sure does improve the ride

 

I have a 2014 F150 with a Bilstein Adjustable Leveling kit set at 2.1". With that I'm running LT295/75R18 which measure out to 34.41" and I have no rub or problems.

 

I have experience with both. A buddy ran his bilstiens at 1.5 with 305's, no issues. I'm at 2.25" with 305's and no issues.

 

What wheels and spacers are you running with that?