The strongest box that should fit straight on is from a Mk3.5 Fiesta
Diesel.
But, it’s quite high geared so you will get nice relaxed cruising on the
Motorway but at the expense of some acceleration.
One from a Fiesta RST with a LSD would also be good but it would only be a
B5 not a IB5.
Or, one from a Mk5 Escort 1.6 or 1.8 ps Zetec, the later of these have the
starter at the rear of the gearbox but a matching starter and a bit of wiring
and it will work.
Not the 130ps 1.8 XR3I as that had the MTX75 gearbox, completely
different.
You may have to mess around finding a combination of clutch release
bearings and clutch.
And don’t go too late or it will have a hydraulic clutch instead of
cable.
1995 was about the latest i think.
My 2+2 ZVH Turbo and Matthew’s (now Roberts) Zetec turbo are both running
Escort Mk5 IB5 gearboxes with Mk4 Escort RST LSD’s fitted into them.