Tailight wiring harness/74 duster

Hey Robert Flippo,
I going to do what you did. I have 1974 plymouth valiant that I can't even start. I am planning on using a 1972 plymouth duster underdash wiring, as well as using the duster's engine harness, and other harness for the tail lights. Do you think that is a good idea? I just don't want to deal with that 1974 seatbelt interlocking stuffs.