[johndeerefarmer]

I am looking for the height of the F250 and F350 in the 4x4 configuration. Also if there is a difference in cab height with the 18" and 20" tires.

 

[manowell]

I haven't seen overall dimensions yet. I'd expect the height difference to be minimal (< 1/2") between the wheels, the 20" rims run with lower profile tires if I recall correctly.

 

[johndeerefarmer]

The standard tires for the SD are:
LT275/65R18e
LT275/65R20e

Heights from an online calculator are:
32.07" for the 18 and 34.07" for the 20's. So 2" overall height means 1" of extra height if I order 20s.

Now if I want the 18's with OWL and All Terrain then you have to get LT275/70R which are 33.16". This would put me about 1/2" over the standard 18"s.