If you have a deck or camera that allows EE, or E to E, you can just pass the video out of the VHS via the normal yellow/white/red cables into your deck or camera, then out of that via firewire into FCP. You may need to select 'video' on your deck (rather than DV) and turn on EE in the menu. Then setup your capture to be 'non controllable device', play the VHS and use 'capture now'.
If you don't have an EE capable deck, you might need a Canopus ADVC, which translates analogue signals to digital and visa versa.