600 quid you are really pushing an rsturbo conversion.
i would say really, about 1500 quid is required, otheriwse you will have problems and the engine no doubt will require a rebuilt and a turbo etc.

a 1.6i escort produces 69bhp. if i were you i would look for a 2L mondeo thats been rear ended or something and buy that for 150 quid. then u get the 2.0 zetec 130bhp, gearbox, ECU, bigger brakes, nice front seats etc etc then weigh whats left in and it will end up costing very little