To the best of my knowledge, stab fuel was never offered on the 747-400F (or the 747-8F). We book-keep a "Typical" freighter mission at about 7 hours, and stab fuel only comes in to play when you're up around 16 hours. BTW, stab fuel had to be deactivated for initial 747-8I deliveries due to a flutter issue (that took quite a bit of work to resolve). New -8I deliveries have stab fuel active, and there is a Service Bulletin to activate it on already delivered airplanes.
While SMOC is technically correct that all -400s (and -8s) have a stab tank, the associated claptrap of pumps, fuel lines, seals, etc. is not insignificant in both cost and weight, so no reason to have it if you're not going to use it. Further, there are MEL implications - if something is INOP, - even optional systems - it needs to be fixed at some point per the MEL. So that provides even more incentive to simply get rid of the stab tank fuel system if you're not going to use it.