I'd try copying the bigip_base.conf and bigip.conf from the 9.3 unit to the 9.4 unit and use 'b verify load' to test the loading of the configs on 9.4. I'm not sure if there were any significant changes to the config syntax. You might need to tweak things slightly. If the interfaces used on the 9.3 unit are different than the interfaces on the 2400 platform you'll need to edit them in the bigip_base.conf. You should be able to do all of this in advance assuming the 2400 isn't in use.
If the 9.3 config references any certs/keys, you'll need to manually copy them from /config/ssl to the 2400 as well.
Aaron