I may be creeping slightly away from the original question, for which I apologise.
On some FMCs in 737s, the FMC will calculate V speeds based on the info you have put in...ZFW, GW, Ambient and Assumed temps etc. Am I correct in thinking that these are balanced field speeds?..I am presuming this as then we overwrite them with our figures derived from the performance manual, which are figures that are runway specific.