My dads truck is a 350 lariat and it is an FX4.....
Is it a 2012?
I specifically read on fords website not once but twice last night. When you go into the build section you will pick your cab then your bed. Then motor and trans(if applicable). Then you pick some exterior bs. Then you go to 'packages'. In the f250 menu it says the fx4 is exclusive to the f250, however it also tells you what you have to buy prior to being able to fit the fx4 package to a DRW f350(3.73 LS rear end and 4x4).
I dont know whether the fx4 is available on SRW 1 tons or not? :shrug: If your dads SRW 350 has skidplates, Rancho shocks, hill descent button, and an E-locker then it does have it.
My last input, I am only reporting what I found on Fords website, as I thought it was odd.