Aside from engine related & Ecu differences:

Door Mirrors
Door crash bars & steel 'safetycage'
Fuel flap on bodyshell
Steering wheel air bag, and passenger one later IIRC (Some late LT's had steering wheel airbag)
Visible Vin no. on dash
Slightly heavier (due to extra crash protection)
Anti-submarine front seats
Door lock shielding with strengthened mountings
Additional bracing for steering column
Seat belt pre-tensioners & grabbers
Different immobiliser system ('Red' key linked to ECU)
Different colour options for paint.