I dont fly the 300 but I believe it has a fairly standard Vref of 120kts. The 400 Vref Is variable depending on the weight and flap setting but it can be in the range of 108kts up to around 130kts. If the flaps dont come down Vrefs around 150kts can be expected and in iceing conditions this can go up to aroud 170kts although abviously this is not a regular occurance thank god.
