I'm starting my st170 conversion on my mk4 escort efi, I have all the mounts to do this and my enitial thought was to use the original bc gearbox fitted to the xr3i efi engine..... but on further investigation it would seem that I need a rear mounted starter gearbox to fit to the st170 engine. Is this true?
can you get a rear mounted starter bc gearbox or will I need to convert to an ib5 gearbox and is this a straight fit? I.e. Driveshafts, gear linkage and mounts.

 

Escort mk6 gti box is what i used.
You can use front start box if you shave the sump, sump will need shaving at the back too for drive shaft regardless of the box (unless you modify to fit the focus box then its a bigger job)

 

Lovely looking escort there