My limited understanding is that the package you got only preps the engine to burn CNG/LPG, and does not include the CNG/LPG tank, piping to the engine and so forth. I could be wrong.
All additional equipment is to be supplied by your after-market CNG installer.
Perhaps you should check with the dealer.
PS the brochure on p. 22 calls Option 98C the "CNG/LPG Gaseous Engine Prep Package."
PS2 -- for instance see here:
PS3 -- See this article and quote below:
Quote from article:
"Each Ford engine that is prepped for CNG/LPG conversion is equipped with hardened valves and valve seats, and Super Duty trucks are equipped with the 6.2-liter V8 featuring a unique bi-fuel intake manifold to accommodate the fuels.
"CNG/LPG factory engine prep costs only $325 before fuel tanks for which the customer chooses the supplier, Additional fuel lines and unique fuel injectors are also up to the fleet manager. The modifications usually run about $9,500 to $12,500, based on tank capacity."