For what it's worth Andy
Personally I would just plumb up the fuel system without the vapour sepperator, I am sure the fuel pump will be more than able to regulate the fuel suply on its own.
As Ash pointed out, the inline filters will tend to sort out any vapour issues
From a study of my redundant, 1.8 CVH carb ( No fuel return outlet ) & a study of the ford fuel layout. The vapour sepperator is for stricter EEC emission compliance. ( Ducks for cover
)
Penty of CVH engined cars not using a return out there mate
