moving engine back

i suspect there's a few of you guys that would have moved your engines back (2lt pinto mk2 escort) for handling reasons, well i'm thinking about moving it back around 10 - 20mm just so i can fit a thermo, how is it done ??, i was looking at just modifying the crossmember where the engine mount bolts to it , by putting another plate on with the slot further back ?? or where the crossmember bolts to the chassis but i wasn't sure if this would play with the steering rack/coloum
any help apprec
any help apprec