depends on what you want from it

not bothered about acceleration and topspeed stick with the one you took out and get it rebuilt

or get one from a mk4 escort with 1.4cvh and put in a s1 limited slip diff and quick shifter (all rebuilt) for good handeling/acceleration then a long 5th (from a dieasel or something) for low rev cruising, moterway etc

a diesel box is rumoured to be the strongest, not sure if it is in fiestas/later escorts but for mk3/4s its not