When using a MTX gearbox on the escort you need a different flywheel as the clutch on the MTX escorts are 240mm.
From what i have seen all mondies use the 240mm clutch.(mk1 and mk2)
Also you have a different mount on the back side of the gearbox so if i am not mistaken you need another subframe also.
On the original subframe you can't mount the different mount or you have to weld it to it.

regards Roy