I have a 2020 FX4 not a tremor and no mods to the suspension. It has the plow prep package and when I measure from the fender to the ground I have a hair under a 2" difference front to rear.
Looking to lift with Carli and the commuter kit says 3.0" lift with my 7.3 gas motor. I am guessing with out the plow prep there is about a 2.5" difference front to rear. I am trying to figure out what
size block to buy from PMF to end up with the Carli commuter installed and the rear end about an inch higher than the front. I want to run the narrow 35 stock tremor tire size in the end nothing
bigger. The truck has the 2" block from the factory in the rear.

I am speculating that the front will be 1.5" higher than the rear with the Carli kit showing 3" of lift. So a 3.5" block in the rear would be level and a 4.5" block in the rear would give me
the 1" high in the rear I am after. Again I am guessing the 3" of front lift is based on a non plow prep truck and I currently have a 2" rear block. Any first hand experience here that may
have done a commuter with a 7.3 gas engine?

 

The advertised lift amounts are just a guideline, these trucks have a ~2+" variance in height from the factory depending on what options they have. Without knowing where in that range your truck sits, it's hard to get a comparison from someone else unless they have the same engine, trans, axles, suspension options, body configuration and other additional options. Have you contacted Carli, or whatever vendor you're gonna use, and ask them? They should know what it takes. The other, more precise, option is to do the front lift, take measurements, then order a block that'll get the rake you want.