whats the diff between wiring harness LX / NOtch

you didnt say which harness exactly you want to change, there is the dash harness which comes thru the dr. side of the firewall and the door harnesses plug to that, then theres the headlight harness which covers all the front lights and then theres the body harness which would go for taillights, fuel pump and rear speakers. little more info and i might be able to help ya out
 
The body wiring harnesses are all the same as long as the model year is the same. Some model years are even interchangeable.

Ford did it that way to reduce the number of parts, which makes the cars cheaper to manufacture.