First off ditch the horrible air intake system, either buy an induction kit, or make one.
Replace the throttle body with a 2.0 item. Sort the exhaust, eBay is your friend!
Best bet is a new engine.
I've never done an escort, but I have a mk3 fiesta that's good for 140+
First choice is which engine. Mondeo mk1 or early mk2. The 1.8 is free revving, more suitable for race type applications. It does not have oil spray bars fitted. So for a good 1.8 you need these bits from the 2.0, oil spray bars, throttle body, cams, ECU. Obvious the 2.0 has these as standard but can be a bit lazy. For full hog you want a 2.0 inlet manifold too. On my fiesta I had to run a focus inlet due to Space. The water pump runs in the opposite direction in a 1.6 - well in a fiesta anyway, so you have to swap that too.
Basically you strip the engine bare, put all the brackets, mounts, alternator etc onto the new engine.
Be safe, make sure your cars brakes are good enough to handle the extra power.